Tag Archives: habitable planets

Wednesday, August 22, 2012 · 12:10 AM

Drought, Part 1: Before 2012

(News & Editorial / Drought, Part 1 – Before 2012)
Mayan Drought & the developing US perma-drought of 2009+ 

 A.  Archaeologists uncover largest ancient dam built by Maya in Central America
July 16, 2012, Provided by University of Cincinnati
Pasted from <http://phys.org/news/2012-07-archaeologists-uncover-largest-ancient-built.html#&gt;
[This image shows excavation of the dam identified by the UC-led team. A collapsed sluice gate is outlined in red. Credit: University of Cincinnati researchers]

Recent excavations, sediment coring and mapping by a multi-university team led by the University of Cincinnati at the pre-Columbian city of Tikal, a paramount urban center of the ancient Maya, have identified new landscaping and engineering feats, including the largest ancient dam built by the Maya of Central America.

That dam – constructed from cut stone, rubble and earth – stretched more than 260 feet in length, stood about 33 feet high and held about 20 million gallons of water in a man-made reservoir.

These findings on ancient Maya water and land-use systems at Tikal, located in northern Guatemala, are scheduled to appear this week in the Proceedings of the National Academy of Sciences (PNAS) in an article titled “Water and Sustainable Land Use at the Ancient Tropical City of Tikal, Guatemala.” The research sheds new light on how the Maya conserved and used their natural resources to support a populous, highly complex society for over 1,500 years despite environmental challenges, including periodic drought.

The paper is authored by Vernon Scarborough, UC professor of anthropology; Nicholas Dunning, UC professor of geography; archaeologist Kenneth Tankersley, UC assistant professor of anthropology; Christopher Carr, UC doctoral student in geography; Eric Weaver, UC doctoral student in geography; Liwy Grazioso of the Universidad de San Carlos de Guatemala; Brian Lane, former UC master’s student in anthropology now pursuing doctoral studies at the University of Hawaii; John Jones, associate professor of anthropology, Washington State University; Palma Buttles, technical staff senior member, SEI Carnegie Mellon University; Fred Valdez, professor of anthropology, University of Texas-Austin; and David Lentz, UC professor of biology.

Starting in 2009, the UC team was the first North American group permitted to work at the Tikal site core in more than 40 years.
What was once thought to be a sluice is outlined in red and is now filled with slump-down debriss.

Detailed in the latest findings by the UC-led efforts are:
•  The largest ancient dam built by the ancient Maya of Central America
•  Discussion on how reservoir waters were likely released
•  Details on the construction of a cofferdam needed by the Maya to dredge one of the largest reservoirs at Tikal
•  The presence of ancient springs linked to the initial colonization of Tikal
•  Use of sand filtration to cleanse water entering reservoirs
•  A “switching station” that accommodated seasonal filling and release of water
•  Finding of the deepest, rock-cut canal segment in the Maya lowlands

According to UC’s Scarborough, “The overall goal of the UC research is to better understand how the ancient Maya supported a population at Tikal of perhaps 60,000 to 80,000 inhabitants and an estimated population of five million in the overall Maya lowlands by AD 700.”
He added, “That is a much higher number than is supported by the current environment. So, they managed to sustain a populous, highly complex society for well over 1,500 years in a tropical ecology. Their resource needs were great, but they used only stone-age tools and technology to develop a sophisticated, long-lasting management system in order to thrive.”

Water collection and storage were critical in the environment where rainfall is seasonal and extended droughts not uncommon. And so, the Maya carefully integrated the built environment – expansive plazas, roadways, buildings and canals – into a water-collection and management system. At Tikal, they collected literally all the water that fell onto these paved and/or plastered surfaces and sluiced it into man-made reservoirs. For instance, the city’s plastered plaza and courtyard surfaces and canals were canted in order to direct and retain rainwater runoff into these tanks.

In fact, by the Classic Period (AD 250-800), the dam (called the Palace Dam) identified by the UC-led team was constructed to contain the waters that were now directed from the many sealed plaster surfaces in the central precinct. It was this dam on which the team focused its latest work, completed in 2010. This gravity dam presents the largest hydraulic architectural feature known in the Maya area. In terms of greater Mesoamerica, it is second in size only to the huge Purron Dam built in Mexico’s Tehuacan Valley sometime between AD 250-400.

Said Scarborough, “We also termed the Palace Dam at Tikal the Causeway Dam, as the top of the structure served as a roadway linking one part of the city to another. For a long time, it was considered primarily a causeway, one that tourists coming to the site still use today. However, our research now shows that it did double duty and was used as an important reservoir dam as well as a causeway.”

[At rights is a view of a Maya-built canal. Pictured is Guatemalan researcher Liwy Grazioso, who has participated in the work by a UC-led team. Credit: University of Cincinnati researchers]

Another discovery by the UC-led team: To help purify water as it sluiced into the reservoir tanks via catchment runoff and canals, the Maya employed deliberately positioned “sand boxes” that served to filter the water as it entered into the reservoirs. “These filtration beds consisted of quartz sand, which is not naturally found in the greater Tikal area. The Maya of Tikal traveled at least 20 miles (about 30 kilometers) to obtain the quartz sand to create their water filters. It was a fairly laborious transportation effort. That speaks to the value they placed on water and water management,” said UC’s Nicholas Dunning.

According to UC’s Ken Tankersley, “It’s likely that the overall system of reservoirs and early water-diversion features, which were highly adaptable and resilient over a long stretch, helped Tikal and some other centers survive periodic droughts when many other settlement sites had to be abandoned due to lack of rainfall.”

UC paleoethnobotanist David Lentz explained that the sophisticated water management practiced by the ancient Maya impacted the availability of food, fuel, medicinal plants and other necessities. He said, “Water management by the Maya included irrigation, which directly impacted how many people could be fed and overall population growth. Accordingly, it is essential to understand the array of canals and reservoirs at Tikal, which conserved water during the annual dry season and controlled floodwaters during the rainy months. These practices allowed the Tikal Maya to sustain relatively high population densities for several centuries. As it evolved, this system of reservoirs was largely dependent on rainfall for recharging. With the onset of the 9th century droughts however, water supplies dwindled, causing the resource base and social fabric of the Tikal Maya to come under considerable stress. These developments may well have contributed to the abandonment of the city.”

Of significance to Scarborough and the entire team are the potential lessons that can be gleaned from identifying a water system like that at ancient Tikal. Said Scarborough, “Water management in the ancient context can be dismissed as less relevant to our current water crisis because of its lack of technological sophistication. Nevertheless, in many areas of the world today, the energy requirements for even simple pumping and filtering devices – to say nothing about replacement-part acquisition – challenges access to potable sources. Tropical settings can be especially difficult regions because of high infectious disease loads borne by unfiltered water schemes. The ancient Maya, however, developed a clever rainwater catchment and delivery system based on elevated, seasonally charged reservoirs positioned in immediate proximity to the grand pavements and pyramidal architecture of their urban cores. Allocation and potability were developmental concerns from the outset of colonization. Perhaps the past can fundamentally inform the present, if we, too, can be clever.

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B.  The Fall of the Maya: ‘They Did it to Themselves’
October 7, 2009, Science@NASA, by Dauna Coulter
Read more at: http://phys.org/news174152911.html#jCp
For 1200 years, the Maya dominated Central America. At their peak around 900 A.D., Maya cities teemed with more than 2,000 people per square mile — comparable to modern Los Angeles County. Even in rural areas the Maya numbered 200 to 400 people per square mile. But suddenly, all was quiet. And the profound silence testified to one of the greatest demographic disasters in human prehistory — the demise of the once vibrant Maya society.

[Photo at left: Mayan ruins in Guatemala.]

What happened? Some NASA-funded researchers think they have a pretty good idea. “They did it to themselves,” says veteran archeologist Tom Sever.

“The Maya are often depicted as people who lived in complete harmony with their environment,’ says PhD student Robert Griffin. “But like many other cultures before and after them, they ended up deforesting and destroying their landscape in efforts to eke out a living in hard times.”

A major drought occurred about the time the Maya began to disappear. And at the time of their collapse, the Maya had cut down most of the trees across large swaths of the land to clear fields for growing corn to feed their burgeoning population. They also cut trees for firewood and for making building materials.

“They had to burn 20 trees to heat the limestone for making just 1 square meter of the lime plaster they used to build their tremendous temples, reservoirs, and monuments,” explains Sever.

He and his team used computer simulations to reconstruct how the deforestation could have played a role in worsening the drought. They isolated the effects of deforestation using a pair of proven computer climate models: the PSU/NCAR mesoscale atmospheric circulation model, known as MM5, and the Community Climate System Model, or CCSM.

“We modeled the worst and best case scenarios: 100 percent deforestation in the Maya area and no deforestation,” says Sever. “

The results were eye opening. Loss of all the trees caused a 3-5 degree rise in temperature and a 20-30 percent decrease in rainfall.” The results are telling, but more research is needed to completely explain the mechanisms of Mayan decline. Archeological records reveal that while some Maya city-states did fall during drought periods, some survived and even thrived. “

We believe that drought was realized differently in different areas,” explains Griffin. “We propose that increases in temperature and decreases in rainfall brought on by localized deforestation caused serious enough problems to push some but not all city-states over the edge.” EnlargeA deadly cycle of drought, warming and deforestation may have doomed the Maya. The Maya deforested through the use of slash-and-burn agriculture – a method still used in their old stomping grounds today, so the researchers understand how it works.

“We know that for every 1 to 3 years you farm a piece of land, you need to let it lay fallow for 15 years to recover. In that time, trees and vegetation can grow back there while you slash and burn another area to plant in.”

But what if you don’t let the land lay fallow long enough to replenish itself? And what if you clear more and more fields to meet growing demands for food? “

We believe that’s what happened,” says Griffin. “The Maya stripped large areas of their landscape bare by over-farming.”

Not only did drought make it difficult to grow enough food, it also would have been harder for the Maya to store enough water to survive the dry season. “The cities tried to keep an 18-month supply of water in their reservoirs,” says Sever. “For example, in Tikal there was a system of reservoirs that held millions of gallons of water. Without sufficient rain, the reservoirs ran dry.” Thirst and famine don’t do much for keeping a populace happy. The rest, as the saying goes, is history. “

In some of the Maya city-states, mass graves have been found containing groups of skeletons with jade inlays in their teeth – something they reserved for Maya elites – perhaps in this case murdered aristocracy,” he speculates.

No single factor brings a civilization to its knees, but the deforestation that helped bring on drought could easily have exacerbated other problems such as civil unrest, war, starvation and disease.

Many of these insights are a result of space-based imaging, notes Sever. “By interpreting infrared satellite data, we’ve located hundreds of old and abandoned cities not previously known to exist. The Maya used lime plaster as foundations to build their great cities filled with ornate temples, observatories, and pyramids. Over hundreds of years, the lime seeped into the soil. As a result, the vegetation around the ruins looks distinctive in infrared to this day.”
Space technology is revolutionizing archeology,” he concludes. “We’re using it to learn about the plight of ancients in order to avoid a similar fate today.”

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C.  Global Ocean Surface Temperature Warmest On Record For June
<http://www.sciencedaily.com/releases/2009/07/090725120303.htm>
ScienceDaily (July 27, 2009) — The world’s ocean surface temperature was the warmest on record for June, breaking the previous high mark set in 2005, according to a preliminary analysis by NOAA’s National Climatic Data Center in Asheville, N.C. Additionally, the combined average global land and ocean surface temperature for June was second-warmest on record. The global records began in 1880.

Global Climate Statistics
The combined global land and ocean surface temperature for June 2009 was the second warmest on record, behind 2005, 1.12 degrees F (0.62 degree C) above the 20th century average of 59.9 degrees F (15.5 degrees C) [1.12F rise + 59.9 average= 61.02F, 2009 combined land and oceans].
Separately, the global ocean surface temperature for June 2009 was the warmest on record, 1.06 degrees F (0.59 degree C) above the 20th century average of 61.5 degrees F (16.4 degrees C).[1.06 rise + 61.5F average = 62.56F 2009 oceans]

[Now, fast forward 3 years to the present; see the growing effects of “the warmest global ocean surface temperature” from July 2009. Mr Larry]
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D.  Punishing drought in Midwest shows no sign of abating
17 July 2012, Reuters, By Ernest Scheyder
Pasted from  <http://news.yahoo.com/punishing-drought-midwest-shows-no-sign-abating-012249337.html&gt;
(Reuters) – Broiling heat blanketed much of the Midwest again on Tuesday, exacerbating the region’s worst drought in more than 50 years and devastating corn, soy and other vital crops.
Across the country’s agricultural heartland, elected officials met with farmers and ranchers affected by the growing disaster promising government relief.

In Missouri, Governor Jay Nixon announced on Tuesday that all 114 counties in the state have been designated as natural disaster areas due to the drought, making farmers eligible for government loans or other assistance. Before Tuesday, 17 counties had received disaster status.

In Iowa, Governor Terry Branstad convened a hearing to discuss the drought and its effect on the state’s pork industry, which relies heavily on corn feed.
“It’s important that we do all we can to help people through this difficult time,” Branstad told local radio station KILJ. “And obviously more rain would help.”

Although weather forecasters said some parts of the parched region might get some rain next week and help pull corn prices off near-record highs, analysts slashed their forecasts for U.S. corn production by another 7 percent on Tuesday, a Reuters poll found.
From Chicago to St. Louis to Omaha, Nebraska, temperatures eclipsed 100 Fahrenheit (37.8 Celsius) and the National Weather Service issued heat advisories across Midwest and mid-Atlantic states.

Many of the heat advisories don’t expire until next week. Temperatures in Kansas City, Kansas, for instance, are expected to hit 104 F (40 C) on Wednesday. In Topeka, the intense heat is drying up soil so far beneath the surface that water lines are cracking.
So far this month, 2,202 heat records have been broken across the United States and another 787 tied, according to the National Climatic Data Center.

Another 14 U.S. cities set new record highs by 8 p.m. EDT (0000 GMT) on Tuesday, according to Accuweather.com, including St. Louis, Milwaukee, Detroit and Syracuse, which all topped out above 100 F.
Those temperatures have contributed to the worst drought since 1956, the National Oceanic and Atmospheric Administration said in a report posted on its website.

FROM CRISIS TO HORROR STORY
About 55 percent of the contiguous United States is in a drought, just as corn plants should be pollinating, a period when adequate moisture is crucial. The United States ships more than half of all world exports of corn, which is made into dozens of products, from starch and ethanol to livestock feed.
“We’re moving from a crisis to a horror story,” said Purdue University agronomist Tony Vyn. “I see an increasing number of fields that will produce zero grain.”
The soonest rain is expected in the Midwest is the middle of next week, said Jason Nicholls, meteorologist for AccuWeather. [Stunted corn grows next to a cattle feed lot in Springfield, rural Omaha, Neb. on Tuesday. The drought gripping the United States is the widest since 1956.
(Nati Harnik/AP)]

The new forecast calls for rains of 0.2 to 0.7 inch (5 mm to 18 mm) around the region, up from earlier outlooks of 0.1 to 0.6 inch.
The dry weather and intense heat likely will continue through August, further damaging the corn crop, AccuWeather said.
Corn prices are at 13-month highs and have surged 45 percent this summer, with analysts expecting the lingering drought to result in the smallest U.S. corn crop in five years.
As the worst drought since the Eisenhower administration begins to expand to the northern and western Midwest, areas that had previously been spared, analysts are slashing corn yield estimates by the hour.
“We need soaking rains now. We need two-to-three-inches and that’s not in the forecast,” AgResource Co analyst Dan Basse said.

EFFECT ON FOOD PRICES
In April concern mounted that near-record spring corn plantings would sharply increase supply and push corn prices below $5 per bushel.
Now, because of the drought, corn prices are flirting with $8 per bushel, and that could boost food prices.

With much of the Midwest pasture laid waste by the drought and ranchers facing climbing feed costs, many ranchers have begun liquidating their herds, which could translate into higher prices for meat next year.

“Based on my conversations with producers, I would say 75 percent of the corn crop in the heart of the drought is beyond help,” said grains analyst Mike Zuzolo, president of Global Commodity Analytics & Consulting in Lafayette, Indiana.

Weather problems were also reported in Eastern Europe and Asia, mirroring drought that dented Argentina and Brazil’s last harvest.
Black Sea grain producer Kazakhstan was preparing for a below-average crop this year due to an “alarming” drought in the country’s main growing regions.

The United Nations food agency said earlier this month that the U.S. drought was expected to see global food prices snap three months of declines in its July figures.
The drought is even harming equipment makers. Shares of Deere & Co, the world’s largest maker of tractors and combines, fell on Tuesday after a JPMorgan analyst said the U.S. drought was likely to harm sales in 2013.
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E.  Global Temperature in 2011, Trends, and Prospects
 18 January 2012, by James Hansen, Reto Ruedy, Makiko Sato and Ken Lo

Click to access 20120119_Temperature.pdf

…Because of the ocean’s thermal inertia, global temperature change caused by solar variability lags solar irradiance by about 18 months. Thus the influence of the sun in 2011 continued to be a cooling effect. However, the sun’s influence will change rapidly to a warming effect over the next 3-5 years…

[During January of this year, Columbia University researchers were predicting global warming to increase over the next 3-5 years–2012, 2013, 2014, 2015, 2016. So if we’re mildly upset with the heat, crop reports and grocery prices this fall, imagine the price-world social situation over, minimally, the next 2 years. – Mr Larry]

Summary
2011 was only the ninth warmest year in the GISS analysis of global temperature change, yet nine of the ten warmest years in the instrumental record (since 1880) have occurred in the 21st century. The past year has been cooled by a moderately strong La Nina. The 5-year (60-month) running mean global temperature hints at a slowdown in the global warming rate during the past few years. However, the cool La Nina phase of the cyclically variable Southern Oscillation of tropical temperatures has been dominant in the past three years, and the deepest solar minimum in the period of satellite data occurred over the past half dozen years. We conclude that the slowdown of warming is likely to prove illusory, with more rapid warming appearing over the next few years.”

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Friday, June 15, 2012 · 12:10 AM

__Chapter 10: SRAPO Survey Templates

(SRAPO/Chapter 10: Survey Templates)

Having reached Chapter 10: Survey Templates, you have been exposed to the information necessary to create:
1.  A template for:
 _ a) the general star – planet system where intelligent life could evolve,
_b) the general climate and other macro environmental factors found on the model planet and,
 _c) u aspects of that planet’s life form morphology.
2.  Approaching this from a different direction: If you hypothesize how an alien might appear, you can plug those characteristics into the SRAPO templates and work backwards to the type world and a range of stars he would likely have developed on.
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Comparing a completed a set of Survey Templates, with the closest similar environment found on Earth, you will have the information to visualize major portions of the alien world in your ‘minds eye’.
As you stand or visually float in that strange new world, look about yourself and see it at dusk.
Its twilight, colors are fading into grays. You look about, while feeling the temperature and humidity; you can generally identify the type of environment you are in. You can tell whether the vegetation is tall or short, thick or spindly, dense or thinly spread about, there may be sounds and smells carried in the air. Large planets are wet, small planets are dry; hot and dry environments have water or temperature as limiting factors; high relative gravity favors short and squat; high relative ultra violet ‘sunlight’ favors protective pigmentation; increasing planetary axial inclination favors life form mobility and hibernation…
The things you sense and see about you are the way they are for a reason.
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SURVEY TEMPLATE I 

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SURVEY TEMPLATE II

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 SURVEY TEMPLATE III


The things you sense and see about you are the way they are for a reason…

 

End of SRAPO

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Monday, April 9, 2012 · 12:10 AM

Chapter 9: Data Compilation

(SRAPO/Chapter 9: Data Compilation)

In Chapter 9: Data Compilation, we’ll draw together data covering the spectrum of our model alien worlds. Using the templates provided in Chapter 10 Templates, you can create a good conceptual model of any habitable planet covered in this study.

Initial Environments Compilation Table
The Initial Environments Compilation Table, below, provides the specific conditions within the physical or biological environments of our model worlds. Firstly, we’ll examine a small section of the table as seen in the cells at left.
The table’s columns are labeled with the APST (average planetary surface temperature); rows are labeled with  Planetary Mass (relative to Earth which =1.0).
Every combination of APST & Planetary Mass contains a box with a list of numbers; these numbers, become line numbers in a list of specific surface conditions found within the environment of that particular planet.
In order to extract information from the table, choose a planetary mass and an associated APST, then read the numbers in the corresponding data box.  If for example we chose a ‘damp’, 0.5 Earth mass planet with a ‘cold’ 0ºC APST, we’d find the data box containing the numbers, see box at left: 12,16,19, 27, 28, 31, 33, 37, 40.

Next, look ahead to The Initial Environments Compilation List and read the associated line numbers, for example;
>  #12 from the Initial Environments Compilation Table is read from line number 12 in the Initial Environments Compilation List, which states; “The planet’s light cloud cover allows for large day and night temperature fluctuations.”
> # 16 in the Initial Environments Compilation Table references, #16 in the List, stating; “The planet carries large polar ice caps, whose formation subsequently increases the dry land area in lower latitudes.”

Initial Environments Compilation Table


Initial Environments Compilation List
1. Life as we know it may not exist.
2. This is a desert world.
3. Free water may temporarily exist in various locations.
4.  High  average surface temperatures and low planetary escape velocity have resulted in most of the liquid surface water being lost.
5.  Life forms display specialized water use adoptions.
6.  Most of the planets free water has probably been lost.
7.  This is an arid world that has been slowly losing its water.
8.  This is an ice world.
9.  This is a cool temperate world.
10. Low temperatures and high escape velocities may have caused this large planet to retain much of its primitive hydrogen atmosphere.
11.  The planet has a nearly continuous cloud cover, which helps depress day temperatures and elevate/moderate night temperatures.
12.  The planets light cloud cover allows for large day and night temperature fluctuations.
13.  This is a water world.
14.  Continents may not exit; islands may provide the only dry land mass.
15.  This large world has three times the water producing mass of Earth, but only 10% more surface area for the water to cover.
16.  The planet has large polar ice caps, whose formation subsequently increases the surface area of dry land.
17.  Small continents and large islands are probably the main land masses.
18.  This rather large planet has two times the water producing mass of Earth, but only 42% more surface area of dry land.
19.  Forest like vegetation may be the most important land crop.
20.  Grass like vegetation may be the most important land crop.
21.  Desert like vegetation may be the most important land crop.
22.  Tropical type forests may be the most important land crop.
23.  Ice caps are present in the planets polar regions.
24.  Permafrost caps exist in the planets polar region.
25.  The planet has large hot, arid deserts in continental rain shadows.
26.  The sense of smell may be more acute than on Earth.
27.  The sense of smell may be less acute than on Earth.
28.  Communication may not be as sound dependant as on Earth.
29.  Communication may be more sound dependant than on Earth.
30.  Communication mat be by sonar using bat like high frequency echo location.
31.  Low temperatures allow for the formation of very complex molecules.
32.  High temperatures threaten complex molecules.
33.  Cool temperatures result in slower chemical reactions and perhaps longer life spans.
34.  Warm temperatures result in faster chemical reactions and perhaps shorter life spans.
35.  The planets rapid rate of rotation helps reduce day to night temperature differences.
36.  The planets slow rate of rotation increases the day to night temperature difference.
37.  Many life forms on this planet would be described as ‘long and spindly’.
38.  Many life forms on this planet would be described as ‘short and squat’.
39.  Animal life has developed an efficient means of getting rid of internal heat at a high rate.
40.  Animal life has developed an efficient means of generating and storing internal energy at a high rate.
41.  The minimum weight for an intelligent Being with a highly developed brain is 40 to 50 pounds (this seemingly critical lower mass would have different      weights on the various planetary models).
42.  The APST is too hot for permanent polar ice caps. With low axial inclination polar regions would have moderate temperatures, but low illumination.

Star-Planet Energy Relationship Table
In the table, Star-Planet Energy Relationships Table, immediately below, each model planet’s mass and the parameters leading to the average surface temperature are compared to provide the resulting associated: % cloud cover, solar constant and albedo; this information will be useful in filling in the templates that follow in Chapter 10.

Star-Planet Energy Relationship Table

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Table of Planet Surface Conditions
The Table of Planet Surface Conditions, large sideways chart below, was derived from combinations of the physical parameters existing on our model planets. On the table, you’ll find planetary mass rows listed along left margin. Reading from left to right along each row, you will intersect with columns of various environmental characteristics and potentials associated with that chosen mass (planet size).

For example, let’s examine a 2.0 Earth mass planet: Reading across the table, the conditions we would expect to encounter on that world would be a:
•  L  (large) potential for wind generating energy,
•  M  (medium) expectancy for wide use of buried organics for fuel, i.e.  petroleum/coal,
•  S  (small) expectancy that solar power will provide much energy.

Further along that same row we find the planet has the addition probable characteristics (among others):
•  G  (great/much) volcanism, as compared to Earth,
•  S  (small) mountain height,
•  and, a 150 pound man on Earth would weigh 204 pounds there.

Continuing to read across the row titled, 2.0 Earth mass,but now looking at the far right side of the table,  we find that with;
•  A 0ºC (-32 º F) APST, the planet would have M (medium) or average (somewhat similar) humidity as found on Earth.
•  At 45ºC (113ºF ) APST, the average humidity would be considered VH (very high)  compared with the Earth average.

The Relative Humidity  sub-table (far lower right) was derived from the considerations that:
a) A graded land-water ratio exists on the study planets and that the water coverage to area dry land ratio increases with the mass of the planet.
b) The greater the mass of the planet, the greater the atmospheric density.
c) As the APST increases, the average  planetary humidity increases. On two planets with the same APST: The smaller planet, with a thin, light atmosphere and relatively small bodies of water, will have lower humidity than a large planet with its heavier, denser atmosphere and large bodies of water.

Comparing the various data in the Table of Planet Surface Conditions, you can see that Man could potentially do quite well on some of the model planets, but would be under considerable biological stress under others; examples can be seen below, from an examination of several variables in the following small table, which was extracted from Environments Table IV.

Condition Selected
Conditions		 Man’s weight Humidity Atmospheric
Oxygen
1. 1.0 Earth,
APST 59ºF		 150 lbs. Medium Medium
2. 0.5 Earth,
APST 32ºF		 103 lbs. Very dry Weak / little
3. 2.0 Earth,
APST 113ºF		 204 lbs. Very high Much / great

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Condition 1:  An Earth like planet, used for comparing Conditions 1 & 2 below.
Condition 2: The planet’s lower gravity results in a human colonist weighing less than on Earth. Man is therefore more mobile, physical activity is less taxing and he requires less oxygen; however,  there is less oxygen available in the thinner atmosphere. The planets habitable equatorial region has temperatures in the 41ºF to 45ºF range. Cool temperatures and low humidity would result in outdoor work conditions similar to those encountered during the Fall season in Earth’s mid latitudes.
Condition 3:  The planet’s higher gravity results in the Human colonists effectively carrying an additional 54 pound body weight. High gravity, high humidity and quite warm temperatures would create an environment more difficult for Man to settle. The planet’s habitable temperature zone basically extends from 50º to 70º latitude and carries a rapidly decreasing temperature across the latitudes, from 99ºF to 41ºF across this band. On the positive side, there is a large amount of atmospheric oxygen which would assist in labor and increase the efficiency of converting organics into electricity, etc. The planet would be more ideally suited to a short (about 4 feet tall) and slender intelligent being. This species expansion would probably require specialized adoptions to rid their body of heat. If the planet orbited a F class star, we might expect to find the alien with darker skin pigmentation, particularly in lower latitudes. Warm blooded animal life on such a planet may not have developed heavy fur coats as are found on Earth mammals.

Table of Planet Surface Conditions

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This study can be used:
1.  To understand star-planet-biological relationships
2.  Determine general planetary environments
3.  Assist in the study of Humans and human technological adaptively under a variety of habitable extraterrestrial conditions.
4.  Back track an intelligent alien, that is, given a description of the intelligent alien’s form you will be able to derive a general model of his home planet, thereby narrowing the range of a) detected habitable star-planet configurations we know of, to date, b) or other Main Sequence stars, from which he came.

See also:
a) The Visual Exoplanet Catalog: < http://exoplanet.hanno-rein.de/complete.php&gt;
b)  The continuously updated list of known multi planetary systems at, <http://en.wikipedia.org/wiki/List_of_multiplanetary_systems>
c) The extra Solar Planets catalog at, <http://exoplanet.eu/catalog.php&gt;

Continued in Chapter 10: Templates

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Tuesday, March 27, 2012 · 12:10 AM

Chapter 8: Into A New World

Biotic Zones
We began this study with a set of basic rules for the development of intelligent tool using life – as we know it. We said conditions must allow for,
a)  the availability of liquid water, b) the planet would need to have an average surface temperature between 0º and 60ºC, the freezing point of water and the temperature at which protien is denatured, and c) the  planet’s mass should fall within the range of 0.25 and 3x Earth’s mass.
We went on to determine cloud cover, albedo and the associated range of solar constants.
We learned how to calculate the planet’s orbital radius, it’s day and year length.
We considered the intelligent alien’s morphology, it’s height, body build and general need for protective skin pigmentation.
We determined what class of main sequence stars could support a life giving ecosphere and learned how long these stars would remain stable for life to develop.
Now it time for our mind’s eye to float down and settle on these alien worlds.
As a child awakening in a new world, we’ll begin to tie together the things we learned from, a) conditions on mother Earth, b) our understanding of bio-organic chemistry, astronomy, atmospheric physics, etc.
Using the SRAPO construct, we’ll now begin to draw and label images for what we may expect to theoretically find on a given alien planet.
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Within complexity lies basic uniformity and structure is related to function. Structural shifts occur within the matrix of complexity, but the matrix remains uniform in function. Mr Larry

The patterns of temperature, precipitation and atmospheric circulation carve out the basic land environments on Earth; we can expect these factors to play equally important, roles on other worlds.
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As we go through our early years of schooling, we learn to associate terms like, ‘equatorial wet forest’ with an area that is hot, wet and jungle like. We call the Sahara, Gobi and Mohave deserts-‘deserts’. Our language can tend to limit our understanding of alien worlds, because we tend to classify environments with a name associated with a mental picture of that environment.
When we are creating planetary models, we need to associate environments with wholistic patterns, combining average planetary surface temperature, atmospheric circulation, illumination levels across the latitudes and biological adaptation. We need to think of an environment as a  process and biological adaptions as shifts with in the matrix of interplay between the given planetary and solar parameters.

By definition, a desert is a region left unoccupied; waste, barren; it is also an arid region lacking the moisture to support much vegetation. Our perceptions of a ‘desert’ relate to the later narrow description, yet in a broader context we can define other deserts, as;
•  Aquatic Nutrient Desert:  Where there is a lack of available nutrients; such conditions exist on Earth’s ocean surface, beyond the continental shelf.
•  Cold Desert:  The continent of Antarctica.
•  Arid Desert:  The arid Gobi, Sahara, Kalahari, Rub Al Kahali, Mohave deserts, etc.
•  Heat Desert:  As located on some of our warmer planetary models; heat is the biologically limiting factor.
•  Illumination Desert: Located near 90º latitude on very warm, low axial inclination planets. Perpetual, extremely low levels of illumination are biologically limiting factors, unless nutriens feed into the illumination desert from biologically active areas.
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The pattern in which each of Earth’s biological communities have developed was influenced by temperature, precipitation, atmospheric composition and circulation, axial inclination, planetary mass, stellar spectral class, the existence of other orbiting bodies (‘moon’, binary star system), etc. If we shift the values of any of these variables on  Earth, there would be a direct impact on the morphology, size and distribution of our biological community, changing them away from what we hyave considered the norm. The norm that we find on extraterrestrial worlds will have developed under their own interplay of planet-star conditions. Intelligent, tool using creatures may seem quite different from what we’re accoustomed to at first glance, but only because they developed from their own unique mix of conditions. They are products from within the same matrix of physical proscesses, just shifted from what is found and called ‘normal’ on Earth. The greater the shift with in the matrix, the more uniusual they will seem, at first.

Equatorial Wet Forest
On worlds with low to medium axial inclination and moderate APST, we can expect to find wet forests in equatorial regions. This zone will have an average temperature 5ºC to 15ºC (9ºF to 27ºF) above the APST and a precipitation rate 50% greater than the planetary average. When compared with the planet’s polar region, the equatorial wet forest will have a greater variation between day and night temperatures, but would remain nearly constant, or only gradually changing on a day to day seasonal basis. Since precipitation would be relatively plentiful, the plant community would have to compete primarily for  sunlight, as a result, some of the tallest plants on the planet would be growing here. If an aerial canopy develops, we could expect a wide variety of shade tolerant plants on the forest floor. The equatorial wet forests moist conditions would be ideal for bacterial and insect life, which would function to bring about the organic decomposition of plant and animal organic material.

Arid Desert Zone
In the high pressure zones above and below the Equatorial Wet Forest exist discontinuous belts of relative arid Desert. The extent  of the Arid Desert across the planet’s land mass will depend on the planetary mass, APST and axial inclination. On our model worlds, any area receiving about 10 inches or less of annual rainfall may be considered an arid desert. Keep in mind that ‘annual’ refers to Earth’s 365 day year. If the model planet has a Sidereal Period twice Earth’s and day length remained the same) the arid desert would only receive half as much precipitation.

Arid Deserts on Earth occupy 14% of the terrestrial environment. They characteristically have a temperature range of 4ºC to 32ºC (39ºF to 89ºF) with an average of 23ºC (73ºF). The Arid desert has a hot, dry climate and is found to register the planets hottest surface temperatures. Plant life which has adapted to the dry, hot climate display biological adoptions for water collection and retention. On the hottest planets,  many desert plants may display reverse phototropism; an hour after the sunrises, the plant may close its leaves, only to reopen them an hour or so before sunset. Succulent plants would have either a small leaf or no leaf at all, with photosynthesis occurring through the plant stem, as in the Barrel cactus and Saguaro cactus. The bulk of the trunk in these plant’s are composed of water storage cells; while the volume of the shoot is large, the surface area is small. This results in a large storage area for the areas biologically limiting factor, water, and a relatively small area from which they can lose their precious liquid reserves.

Non succulent plants will be modified with leathery leaves, thick cuticle layers on the outer surfaces of their leaves, they may have the ability to fold and curl, also leaves will likely be small. An example of a plant displaying many of these characteristics is the Creosote bush found commonly in the US southwestern arid desert.

In arid deserts, both succulent and non succulent plant species would have extensive root systems for water collection and potentially as locations for water storage.

Chemical inhibitors may also be used to maintain territory. This would result visually, in a more or less even spacing of the plants across the desert.

Other plants which have adapted to the Arid Desert might undergo their entire life cycle in that brief period when moisture was available. These ‘annuals’, with their fast growing shoots would die after the end of the moist season, leaving their seeds and/or a viable root system to lie dormant until the next moist period.

Animal life in the Arid Desert would tend to be either the small burrowing variety or larger, but thin. Due to the extreme temperatures, large animal life would have small body volume to large surface area ratios.

In these climatic conditions, both plant and animal life will have made specialized adoptions to reduce water loss; these adoptions may be biological or by technique or both.

Prairie & Grasslands
The condition of a temperate climate coupled with erratic and limited rainfall can extend grassland communities from the equator to near the polar region. On Earth, the grasslands have an annual precipitation rate that falls between 25%  (10 inches) and 75% (30 inches) of the planets average. These areas are typified by small short lived plants, mainly annual and perennial herbs, relatively little rain, good fertile soil and numerous large herbivores.

In temperate regions on alien worlds which receive similar precipitation, we might expect to find similar types of biological adoptions. We might also expect to find such regions under agricultural use as fields or pasture amongst intelligent species.

While the plants and animal living in these zone will certainly look exotic, we will understand from their distribution and general adaptations to the limiting factors in the environment that they fill the same or similar roles in the ecology of the communities in which they live.
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Cool Forest The temperate forest regions of Earth’s mid latitudes are extremely complex in their makeup and adoptions to temperature and moisture availability. Across broad regions of our own planet, the cool temperate forest experience temperatures ranging from -34ºC to 27ºC (-29ºF to 81ºF) with an average of 3ºC (37ºF) and precipitation rates of 10 to 60 inches per year.

The ability of a plant to survive freezing temperatures is called ‘frost resistance’, this ability varies widely among different species and is normally seasonal.

On cool and mild APST planets with low rates of axial inclination, frost resistant species would be found primarily in the mid to higher latitudes. As we encounter increased rates of axial inclination, frost resistance would tend to migrate closer to the equator. On planets with a very high  degree of axial inclination and mild temperatures, we would  find most plant species specialized with both frost resistance and heat tolerance. On such worlds, we might find plants going through a growing cycle where their cells are partially filled with an electrolyte during the winter, forming a biological antifreeze. As winter gives way to spring and spring to summer, the electrolyte might gel into a paste, reducing water loss. Then as the climate cooled, the paste would dissolve back into antifreeze.

Ice Caps, Tundra and Snow Fields
On many of our model worlds, we should expect to find the existence of ice caps. On the cooler worlds we will find thicker ice caps in the polar regions, with snow fields extending in various coverage down to mid latitudes. Cooler planets with a low degree of axial inclination will have permanent ice caps. Warmer planets, with a high degree of axial inclination, will have ice sheets and snow fields that migrate with the season, similar to winter snow across northern latitudes on Earth. On planets with a high degree of axial inclination the plant and animal life with have a high degree of cold and heat tolerance, species migration may be an important part of many large animal life forms and hibernation a retreat from the cold for most of the smaller less mobile creatures.

Ice caps are bordered by Tundra in terrestrial environments. As we move up through the APST range, we could find the Tundra and Ice Caps at progressively higher latitudes. Eventually the ice cap is replaced by diminished snow fields. As the APST approaches 60ºC, the Snow fields melt away and are replaced by a low illumination environment.

If we compared two planets of the same mass and axial inclination, the planet with the higher APST would have the smallest ice cap. If we compared two planets of same mass and APST, the planet with the smallest axial inclination would have the largest permanent snow fields.

On warm planets with moderate to high axial inclination, the ice cap may completely disappear during that hemisphere’s summer. The activity of the biotic community on alien worlds will be similar to that on Earth as each season is experienced. The hemisphere entering Spring, a time of increases sunlight and warmth,  will come out of winter dormancy and experience growth.

In the hemisphere entering Fall, the biotic community will be gearing down for the approaching Winter. The plants will winterizes, the animals will migrate, build up energy reserves, prepare for hibernation and/or utilize other adaptive mechanisms.

On planets with approximately a 30ºC APST, we may find the absence of true ice caps. In their place may exist the relatively more temperate permafrost fields with perennially frozen ground or nearly permanent frost.

Frost caps require an annual temperature of about -3ºC (26ºF) or less in order to exist; however, the temperature range over the entire area may run from -36ºC to 4ºC (-32ºF to 39ºF). Precipitation in these regions is under 15 inches per year. Climatic conditions in the permafrost zone is are cold and dry, with long winters and cool summers.
[Illustration at right: Ice Cap & Snow Field expansion on a cool planet with varying degrees of axial inclination.]

On any world with a permafrost region either covering the poles or circumventing the icecap, an explorer would find large expanses of flat land and rounded hilly terrain, where the effects of freezing and thawing would have reduced rocks to small particles. The soils of these regions would be poorly drained and poorly aerated on planets with low axial inclination and just the opposite planets with high axial inclination.

Remember, if the planet were orbiting a relatively cool G9 or K0 spectral class star, it’s orbit would be near the star, providing a short year. If the planet orbited a much hotter, F24 or F4 star, its orbit would fall further from the star giving it a year perhaps twice as long as our own, hence a ‘quarter year’ of about 6 months- plenty of time for small plants to go through their life cycle, or even a couple of generations.

Permafrost environments are typically a low energy areas offering little year around food to the larger animals. Most of the animal life consists of small burrowing types with insulated feet and various seasonal visitors. I suspect that small animals would inhabit permafrost regions on planets orbiting cool stars. Larger migrating species would be more important on planets orbiting hotter stars, where the growing season is longer, where a larger deposit of biomass has accumulated and where the season length would allow the larger species to migrate.

Small (short height) plant life would only have a few months, depending on the planets sidereal period (length of year) to carry out their life cycle before
reduced temperatures would bring about dormancy.

Planetary Bio-Zones, Plant Growth & Limiting Factors 

On all of our model worlds, we could expect to encounter a mix of the following environments: cold, warm or hot arid deserts, rivers, marsh land, fresh water lakes, bays, hills, meadows and plains. We would expect to find a vast assortment of analogous physical surface structures, i.e., rock, sand, gravel, humus with partially decayed organic material, cliffs, etc. We would see common atmospheric phenomena, the parent sun in the sky, stars visible at night, fog, rain, snow, wind, clouds, storms-all with great variation in quantity, frequency and  intensity as the stellar and planetary parameters were varied.

The biological community whose evolutionary histories track back through a particular environment, will display adoptions peculiar to that environment. It’s also reasonable to believe that similar environments on different alien worlds will tend to carry life forms who share somewhat similar morphological and very general behavioral patterns.

Atmospheric Circulation & Biotic Zone Diagram
The following Illustration: Atmospheric Circulation and Biotic Zones provides a general view of the effects of precipitation and atmospheric circulation.

This planet’s biotic communities exist somewhat in bands that tend to change with latitude. Earth type vegetation has been symbolically drawn along the planets curvature in an attempt to trigger a conceptualization of the processes that occur in each biotic zone. While studying this illustration, keep in mind that:
•  As the mass of the planet increases, gravity increases, resulting in generally shorter, more squat looking plants and animals. Also, the land to water ratio decreases-leading to less dry land and more water on the larger planet.
•  If the APST were increased, the biotic zones would migrate toward the poles. Conversely, decreasing the APST would cause ice caps, tundra and snow fields to expand toward the equator pushing all other biotic zones before them. With a very low APST, the wet tropical forest might simply disappear, giving rise      to an equatorial temperate forest.
•  Biotic zones and land-to-water ratios expand or contract as we adjust the various parameters examined in this study.

Biotic Zone diagram

In relation to the Biotic Zone diagram, also see below, the Relative Precipitation-Solar Radiation-Vegetation diagram and the  Latitude – Temperature Tables.

Relative Precipitation-Solar Radiation-Vegetation diagram

Latitude – Temperature Table

High latitudes Mid latitudes Low Latitudes
Temperature may  constrain life. Combination (local   climate) Precipitation constrains life
High annual   temperature variation. Temperature   variations greater inland than coastal. Low annual   temperature variation.
 Low daily temperature variation. High daily   temperature variation.
Low storm activity. Storm rates increase over land, decrease over sea. High storm activity.


Spring: Land heats up fast developing low pressure areas, sea develops a high pressure system.
Fall: Water remains warmer and develops a low pressure system, high pressure developers over land.
Planets with low to moderate axial inclination (little tilt) will generally provide increasingly lower temperature, stable temperature bands as one moves from the equator toward the poles.

Planets with a moderate degree of axial inclination will experience pronounced seasons as the year progresses. During the summer, that hemisphere tilted toward its sun will experience seasonably higher temperatures. A half of their year later, when the previously warmer hemisphere is tilted away from its sun, it will experience seasonably low temperatures. These seasonal temperatures create an overall average temperature for each latitude and region.

On a planet with no axial inclination, each latitude would still have a narrow annual average temperature between it’s ‘summer highs and winter lows’, this derives from the probability that the planet’s orbit is not a perfect circle about the parent star, a condition similar to Earths orbit. The extremes for all latitudes, on either side of the average, would be eliminated by the lack of axial inclination.
On Earth, the average annual temperature for a given latitude is that temperature the latitude would have if Earth had a 0º, instead of 23-1/2º axial inclination.

Shown in the Biotic Zone Table below, are the annual average planetary surface temperatures for each latitude. Since we have eliminated the temperature variation by using ‘average temperatures’, we can in effect say that if these temperatures were maintained throughout the year, that the planet has no axial inclination.

Lets now say that on any planet where there is no axial inclination, the temperatures vary with latitude just as they would on a Earth with no axial inclination. If this is so, we can compare temperatures with latitude for planets displaying all the APST used in this study. We should  remember that the resultant temperature models provide:
•  The annual average temperature for each latitude on a planet with 0º axial inclination, or,
•  the annual average temperature for each latitude as derived from the overall seasonal variations on those planets with axial inclination.

In the Biotic Zone Table, compare temperatures (in degrees Fahrenheit and Centigrade) with latitude for each of our planetary models.
Earth equivalent biotic zones have been colored into the chart showing the migration of  plant life related to APST.
The temperatures given in the table were calculated as follows:

Example #1: 140ºF (hot planet’s APST) – 68ºF (Earth’s APST) = 72ºF difference (on hotter planet)
Therefore, 72ºF hotter (in general) + 81ºF at Earth 0º latitude (equator) = 153º F at 0º latitude (equator) on hot ASPT planet.

Example #2:  68ºF (Earth’s APST) – 32ºF (cold planet’s APST) =  -36ºF cooler difference (on cooler planet).
Therefore,  -36ºF cooler (in general) + (-4ºF on Earth at 70º latitude) = -40ºF at 70º latitude on the cold planet.

Look across the top of the Biotic Zone Table to locate 113ºF, then read down the column to find the approximate surface temperature at a given latitude. On a planet with an APST of 113ºF, the equatorial temperature would be about 126ºF, at 60º latitude it would be a warm 80ºF  and a cool 41ºF at 70º latitude.

Drawn to overlay the preceding table are the color coded, approximate temperature and latitude boundaries, of the various biotic communities found on Earth. I’ve extended the APST range an additional 15ºC on either side of the conditions used in this study to demonstrate the serious deterioration of the planets habitability, see double blue and double red verticle lines toward either side of the chart.
In the column at far right, Earth’s APST (average planetary syrface temperature) and general biotic conditions per latitude have been included for comparison.
Note that the biotic community we are accustomed to on Earth, would be seen to shift toward the planets equator with a reduction in the average planetray surfave temperature; conversely, the biotic zones would shift toward the poles with an increase in APST.

In order to better understand the migration of biotic zones and the general climate of our model planets, I’ve included the illustrations below showing and equatorial and polar view for each 15ºC change in APST within the SRAPO filter parameters. An Earth model has been included for comparative reference.

Model illustrations on the left, provide an equatorial view of the planet with latitudes shown on the extreme left and temperatures on the right.
The models on the right, are shown in a polar view. The numbers entered above the pole are latitude and number below are the average temperatures for the given latitude.

ILLUSTRATION: APST, LATITUDE and ENVIRONMENT MODELS.

Environmental Limiting Factors & The Plant Community
The planetary models we looked immediately above, have no axial inclination, we were determining the average temperature for a latitude;  the length of the day to night cycle made no contribution. The parent star will rise and set in the same locations daily. Each day at local noon, the sun will have risen to it’s highest point in the morning sky and will begin its move lower in the afternoon sky. The elevation the sun rises to above the horizon al local noon will depend on ones latitude on the planetary surface.

On a planet with no axial inclination and 0ºC APST, plants in the equatorial zone, below 25º latitude, would be exposed to nearly perpendicular sunlight at local noon.

On planets with0 to 30ºC APST, most of the plant communities exist below 60º latitude. In these locations, the noon sunlight comes from a position relatively high in the sky. This results in the tropical and cool forest developing ‘ vertical light gathering stratification’. Hence we would find fungi located in the lower strata, rising above the fungi would be the shade lovers, then the shade tolerant and finally a canopy of sun seekers.

On 0º axial inclination planets, with 45ºC to 60ºC APST, the  majority of the plant community exists above 45º latitude. Under these  conditions, the tropical and cool forest would tend to develop ‘horizontal light gathering stratification’. On the equatorial side of the forests reaching deeper and deeper into the hotter zones, plants would decrease in size or biomass, attempting to adapt to extreme temperatures. On the polar side of the forests, plant life would again decrease in size or biomass, but this time light would be the limiting factor.

The following, illustration, Relative Plant Size and Biomass Per Unit Area, uses APST, latitude and various biological limiting factors to assist in developing a feeling for plant height and /or biomass per unit area, for various latitudes across a planet’s surface.

Also, remembered that gravity affects height, so that the largest or tallest plants on a 3.0 Earth mass planet will be considerably shorter than the tallest plants on a 1.0  or 0.5 Earth mass planet—that is, if all parameters are equal except planetary mass.

The  0ºC APST’ model in the  illustration shows short plants growing at around 30º latitude, this planets tundra zone. This biologically limiting, cold environment, rapidly gives way to a cool forest which extends from about 25º ‘north (and south’) latitude to the equator. With the sun passing nearly over the habitable equatorial zone, we would expect to find the plant communities of the cool temperature forest well developed into vertical light gathering strata.
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Illustration: Relative Plant Size and Biomass Per Unit Area

The 60ºC APST (140ºF average planetary surface temperature) model has short, ‘shade loving’ plants in the biologically limiting, dimly lit, twilight like polar region. With a decrease in latitude and subsequent increase in elevation of the mid day sun, the cool temperature forests develop a fierce competition for light. Around 60º latitude, the damp. Warm and fairly well illuminated conditions produce a tropical type forest canopy which carries the tallest plants on the planet. Below 60º latitude, increasing temperatures tend to overcome moisture availability where upon plant size or biomass per unit area must be reduced to thwart starvation.
Approaching 30º latitude, the high pressure system creates arid conditions. This area is not only arid, but extremely hot, with air temperatures 10ºF above that required to destroy protein. From about 30º latitude and down to the equator, temperatures tend to become the biologically limiting factor. (Note: For comparison, its recommended that we turn adjust the water temperature in our home hot water tank from 140ºF to about 120ºF to reduce the chance of being scalded).

On a planet with a large mass, i.e. 2.0 to 3.0 Earth mass, the dry land area is quite small compared with the area covered by water, therefore, at 60ºC APST, a dry land area located at 30º latitude would not be arid, it would be for us, an environment of extreme heat and severe humidity. On such a world, at 30º latitude, our bodies would feel like they were in a 140ºF sauna. We wouldn’t feel comfortable until we relocated to 70º latitude where 70ºF air temperatures would be found; equivalent to being above our ‘Arctic Circle’, in Finland, Alaska, northern Russia, northern Canada, Greenland.

Continued in Chapter 9: Data Correlation

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Tuesday, February 21, 2012 · 12:10 AM

Chapter 7: The Morphology of Intelligent Life

The parameters of this study are within the limits under which matter can become ‘living’ and life forms can thrive.

Plant and animal life are highly organized conglomerates of matter which are subject to the laws of chemistry and physics. These laws carry restrictions when dealing with life, restriction which allow us to say: The complex molecular structure of a cell will become disorganized unless it can obtain external energy and effectively use it internally to overcome the continuing process of degeneration.

In order for there to be a pool of larger animal life forms, from whence our intelligent alien is drawn, there must be a complex ecological base in existence on the planet.

On the alien world, as on our own, external energy must be tapped for maintenance of internal order. The prime energy source on any of our model planets is radiation from the parent star.

Primieval development
In the primeval seas of alien worlds, it is reasonable to assume that biochemical adoptions favoring the use and storage of soar radiation would be drawn into the mainstream of the evolutionary process. These adoptions may well resemble chlorophyll in function, by converting low energy molecules into high energy molecules in the  presence of solar radiation and finally by moving and storing the resulting molecules for growth, reproduction, metabolic and regenerative use.

Life forms which convert and store solar energy (Producers) are  necessary as food for species which develop without the ability to produce their own food (Consumers).

Once the producers have made the necessary adoptions to live on land, their diversification and spread would begin. They would become more and more specialized, moving into virtually all planetary environments where life functions were possible. Meanwhile, following the expansion of the Producers, would be the Consumers. Prior to leaving the sea, the Consumers will have already begun to diversify into herbivores and carnivores, this process would continue on land.

Morphological considerations
On Earth, certain morphological relationships exist amongst the larger animals, which share a common or similar food source:

Its is common to find that the larger Herbivores graze in groups, that they are fast runners, have horns or antlers to assist in food collection, protection and mating behavior; and have teeth especially suited for grinding.

The large Carnivores also share common characteristics; they are very fast short distances runners, have  powerful front limbs with sharp nails and powerful jaws with teeth adapted for holding, cutting and chewing.

On any of our theoretical planets, specialized adoptions will exist which are derived from the life forms heredity, diet and environment.

Since the environments we’re studying can exist on planets around F2 through K1 stars and because these stars exist in profusion through out the galaxy, we can expect to find comparable structures performing similar biologically important functions, essentially everywhere.

We can expect to find intelligent aliens with some mechanical means of cutting or grinding their food. We can expect to find that within their bodies is an area where food is chemically processed before assimilation. They will need an internal or external framework to support their organs and muscles. They will have a nervous system with sensors so that they can find food, avoid being eaten and form social groups to pursue intricate social and engineering objectives.

Digestion
One way to explore alien morphology, is to follow a piece of food through its body, while discussing the alien form in terms of ‘shape being related to function’ and biological adaptation.

On a distant world, a creature which had developed tool using intelligence, encounters a large morsel of food. The food item could be a fruit, a large seed pod, tuber, root or ‘roast’. This large tough piece of food needs to me mechanically cut, broken up and ground or softened prior to exposing it to chemical attack within the body. The purpose of mastication is to increase the total surface area of the food so that it cane be quickly and efficiently broken down into  the aliens chemical-biological building blocks. In order to accomplish this, a grinding and cutting surface is needed, this surface could be provided by specialized bone, teeth or even a beak,  and would need to be imbedded in a hard surface to protect the alien’s softer tissues from the forces exerted in mastication (chewing process).

The energy to operate the ‘chewing’ mechanism would have to be exerted through a muscle tissue which has the ability to repeatedly contract. We might envision a hydraulic system operating these grinding surfaces; however, muscle tissue would still be needed to power and control the flow of hydraulic fluids.

The cut and ground food would then pass into a short term storage area. This organ would be a holding area in which digestion may or may not begin. It is also possible that swallowed food would be channeled directly into an intestine.

The major digestive organ would have accessory organs associated with it which provide the various acids and enzymes necessary for digestion. This intestine like organ would have a large surface area covered with capillaries from the aliens circulatory system.

Digestible products would be chemically reduced to primary and special biochemical building blocks, absorbed through the intestinal wall and carried through out the aliens body. Indigestible materials would pass through the digestive organ for excretion..

“Food” chemicals absorbed from the circulatory system would be used by the bodies cells for construction of protoplasm and the release of energy. Inorganic salts, minerals and water would be used for the maintenance of his internal environment,  including pH and his endo or exoskeleton, etc.

Circulatory system
The circulatory system would be a network of various sized distribution vessels joining a pump or system of pumps. This system would be responsible for circulating food to the body’s cells, carry cellular waste to an organic filter for excretion. It would also play an important role in the body’s defense against infection as well as carry oxygen to the cells for oxidation of foods and carry off the byproducts of respiration.

Respiration
Our model alien will need a respiratory system to move oxygen into the body. In small animals, a trachea system may exist which would operate by passive diffusion, but in larger animals, the body mass is such that oxygen demands are too great for such a method.

Its necessary to realize that on a majority of alien worlds that large, intelligent, tool using life would have developed with an active method of drawing portions of the atmosphere into their body.

As the inspired portion of atmosphere enters the body, it may be cooled or warmed as it passes over internal surfaces. Within the air entry and-or preconditioning passages, there may also be a filtering system of hair and mucous to remove small particulate matter.

The point at which air enters the bod,  ‘the nose’ maybe more conspicuous on aliens from colder, drier and dustier worlds and less conspicuous on warmer, moister worlds.

After the air is regulated for temperature and humidity, it would be drawn into an organ having a large surface area. This respiratory organ would be tied directly into the circulatory system for the transportation and absorption of oxygen and removal of byproducts from cellular oxidation. Entering the circulatory system, the oxygen could be carried to the cells as a gas, dissolved in the circulatory medium or attached to a respiratory pigment. On Earth, the common respiratory pigments are compounds of copper or iron. After oxidation had taken place in the cells, some of the by products would return to the lung for removal into the atmosphere.

Mechanical support
The model intelligent alien will need a rigid or semi rigid skeletal system for mechanical support of his body’s leverage system.\An exoskeleton, covering the entire body would be effective protection against cuts and abrasions; however, large life forms grow so fast that the exoskeleton would have to be shed many times during the maturing process. In those times when each old, outgrown exoskeleton was being shed, but before the new one had grown in, the alien would be vulnerable to predator attack.

A biologically more advantageous scheme would be to have an endo skeleton. One that does not render the possessor unduly defenseless during anytime of its life. Another advantage of the endo skeleton is that it leaves the skin exposed for maximum environmental sampling.

The endoskeleton would probably offer a means of protection for those vital organs which would lose efficiency if they were molested by bending and twisting and those requiring more or less continuous movement, such as the heart and lungs. Protection can be gained by a bone or cartilage cage surrounding the cavity where these organs would be carried.

The alien body may also have exoskeletal structures, such as claws, nails, horns, hoofs, beak, scales, feathers, hair, fur, boney plates, teeth, etc.

Appendages
Our intelligent tool using alien will have legs for locomotion and jointed arms with jointed fingers for fine manipulation.

Where as at least two legs are necessary, we cannot fully  overlook quadrupeds intelligence. In Man and the primates, the front legs have become specialized modifications resulting in arms. So if we assign our alien four legs and two arms, we must remember that his distant ancestors had six legs. Would a planet with much higher gravity favor selection of species with  six legs?

On the planetary models, higher gravities would be more simply overcome biologically by reducing body weight, increased muscle mass and a tougher skeleton than by many legs.

Among bipeds it seems reasonable to assume the existence of ‘feet’ to facilitate in balance and locomotion.

The number of arms the alien may have depends somewhat on coordination and efficiency. It seems likely that with a system of bilateral symmetry two arms would suffice in practically and survival task offered by the environment. Once again, if we postulate an alien with four arms and two legs, its ancestors would have had six legs. Extra appendages require greater nervous complexity and exact a good deal of energy from the organism for their maintenance.

Hands with boney projections and attached muscle offer a good system of leverage. For a good grip, at least three fingers are needed, one  in opposition to the others. The number of fingers could be increased to perhaps seven or eight, but beyond this the advantage becomes questionable.

Sensory apparatus
Among the aliens arsenal of environmental sensors we can expect varying degrees of development in structures providing sight, hearing, smell, taste and touch-all factors that put any mobile life form into a sensory feedback loop with its surroundings.

Solar radiation is by far the greatest energy source in the environment, the velocity of light along with the reflective properties of matter make it a very important element in sampling ones surroundings. On Earth, various forms of eyes have developed on creatures with very different evolutionary histories, common examples are the common housefly, squid, andMan.

The structure and image perceiving properties of the human and squid’s eye are very similar, illustrating the parallel, yet independent development of these very complex structures.

Stars of spectral class F2 through F6 have a higher proportion of their output in the violet end of the light spectrum, while G8 through K1 stars have a greater proportion of their  visible light output in the red end of the spectrum than does the Sun. Its possible that aliens developing on worlds orbiting F2 to F6 stars may see a little farther into the violet, while those from call G8 to K1 stars may see into the infrared.

The number of eyes an intelligent creature has will not be highly variable. One eye does not provide the depth perception necessary for survival. Two eyes give adequate depth perception and a third eye would slightly increase this perceptive ability. Increasing the number of eyes beyond two or three does not increase survival at a linear rate since there is a diminishing return for the biological investment.

The ability to sense sound is valuable in communication and for locating the general location of other animal life. On the smaller planets with thinner atmospheres, sound may not play as important a role as it does on earth, where as on the larger planets with their denser atmospheres, sound may be more important.

With auditory sensors on either side of the body, the alien would be able to determine the direction a sound emanated from, he could then bring his eyes into play and search for detail.

The sense of smell will probably also play an important role. Olfactory sensors are actually chemical sensors that analyze the immediate atmosphere. They are not as important for locating the exact position of a chemical emitter as they are for determining its general direction and identity. On the smaller, lightly atmosphered planets, this may be not as well developed as on a larger planet with denser atmosphere.

The brain (and it’s housing)
Since a good deal of survival depends on fast reflexes and quickly transmitting incoming information into personal action, the shorter the time lapse between stimulation and reaction, the greater the chance of survival. Its reasonable to place the brain and major environmental sensors close to one another so that in an emergency, the sensors can relay information rapidly to the brain for processing.

We might find that in most intelligent, tool using aliens that the major environmental sensors, the brain and mouth are all located in a protected container that sits atop a semi flexible shaft. The free maneuverability of this portion of the body is important because of the speed at which the sensors could be brought to bare on a point. This location would reduce the input to movement time and the energy loss that would go with sensor grouping in the body’s trunk

The importance and physical sensitivity of these organs would preclude some means of protection such as an endo or exoskeletal vault. Such a structure would give adequate protection, provide a rigid base for the cutting and grinding surfaces of the mouth and serve as a rigid source for the attachment of the muscles which operate the masticating apparatus.

Brain weight, body mass & intelligence
In order to form an understanding of the relationship between brain weight, body mass and intelligence, lets momentarily look at the  relationship of these variables on Earth. The characteristic weight of the human brain is 2.86 pounds, while the average human adult has a body weight of 150 pounds, giving a brain to body ratio of about1:50.

In the animal kingdom, as body weight is increased above this ratio, the intellectual capacity of the brain is reduced. The reduction occurs because more neural tissue is being used to control the expanded body functions. Some examples of a decreased brain weight to body ration can be seen in the chimpanzee (1:150), gorilla (1:500) and elephant (1:1000).

On the other hand, if we reduce the body weight appreciably below the1:50ration, we find the animals overall weight has decreased to such a point that there simply isn’t enough neural tissue available for the complexity of intelligence. This can be illustrated by several types of monkeys, which have a brain to body weight of 1:17, and whose total body weight is less than the human brain!

Our brains have about 10¹º neurons with each neuron making  about 100 connections, giving us a possible information storage content of 10¹² bits.

Its quite possible that an intelligent alien would have about the same brain to body ratio. Variations in his physical environment might favor increased or reduced cell size, in effect making him larger or smaller; although gravity alone can accomplish the body size variation. The alien might fall right on the 1:50 ratio yet have as lower or higher degree  of neural activity, thus giving his species a lower or higher relative intelligence.

Alien height
The average height of an alien species on a planet similar to one of our model worlds cannot be known without observation; however, we can make some interesting, possibly relevant speculations.

We know that an intelligent, tool using alien must have a sizeable body mass or his brain would be too small to carry the number of neurons necessary for intelligence. On the other hand, a giant would have such a large body mass to brain ratio that much of his brains capacity would be used in body operation,  at the cost of ‘thought’.

The brain to body mass ratio’s need for about 10¹º  brain neurons tells us that an intelligent alien will probably fall within an ambiguous height range between extremely small’ and ‘extremely tall’, compared with Man (see ‘Alien Height’  illustration below).

Tests have shown that gravity affects growth length.

Its not unreasonable to assume that on a large planet with its high gravity, that over the eons, survival would have come to favor short creatures. A short muscular creature who trips and fall on a high gravity planet would receive on the average less injury than a tall creature. The shorter creature would not fall as far, nor hit the ground as fast or with as much force as a taller creature. Being incapacitated periodically from impacting on hard and irregular surfaces, is not a good survival strategy for any species. Higher gravity worlds may physically favor land dwelling life forms that have developed a low center of gravity. Conversely, low gravity planets may physically favor land life forms which are tall by comparison to Earth.

I’ve made the assumption, that as a rule of thumb, when moving between planetary models,  for each increase or decrease of 0.25 relative Earth gravity, that the average height of an alien intelligent species will inversely increase or decrease about twelve inches. This rule of thumb is only to be used for intelligent tool using life developing on planets within the parameters of this study. This assumption provides us with a general correlation between intelligent alien height and the mass of the home planet.

The illustration, Alien Height and Surface Gravity, below, is meant only as a guide to conceptuale your thinking. In the absence of data, we can at least  say that it does not violate the brain to body mass ratio and considers gravity and length studies.

Alien build
In this section we’ll attempt to draw a generalized relationship between the APST (average planetary surface temperature) and the average alien physique, or build.

Its true that surface temperatures vary with latitude on our model planets and that there will be a great variation in temperatures across the  face of the planet. What we will attempt to find is a potential relative average alien build for any given APST and planetary mass combination. The result of our inquiry into alien body build should be seen as “this is what the physical environment might tend to favor”. The more an environment tends to favor a particular biological response, the more frequently that biological response will be found to occur.

There seems to be a general trend in that many life forms in a hot climate have a large body surface area to body volume ratio. This says that ‘thin’ animals are best adapted to hot climates. In hot climates internal heat must be dissipated easily, thin bodies with a large surface area afford the means to do so.

In cold climates, many animals have developed a small surface area to body volume ratio. These bulky animals generate a lot of internal heat and lose it slowly to the cold environment through their bodies reduced surface area.

General physique on hot and cold planets

Table: Heat Storage & Dissipation, Based on Body Size

PARAMETER HOT COLD
Trunk height (inches) 18 18
Trunk diameter (inches) 12 18
Trunk radius (inches) 6 9
Volume (cubic inches) 2034 4578
Area (square inches) 678 1017
Relative volume 1.0 2.2
Relative area 1.0 1.5

In this table, which compares surface area and body volume ratios, note that the bulky cold environment alien has 2.2 times the body volume of his thinner hot environment counterpart, but only has 1.5 times the surface area to lose the heat from. In a cold, low energy environment, a relatively bulky body would provide an energy savings advantage over a thin body. In a hot environment, the bulky alien would be at an  energy disadvantage. Trying to dissipate relatively large amounts of body heat into a hot environment through a comparatively small surface area, he would be faced with reduced activity or potential heat stroke.

Diagram: General Body Build of Intelligent Alien compared to APST & Planetary Mass

The diagram above, allows us to make some interesting speculations regarding the alien physique:
•  The average intelligent Being from a 0.25 Earth mass planet with 60ºC APST might be very thin and stand around seven plus feet tall. His tall, thin stature would make him appear almost mantis like.
•  A biped Being from a 0.25 Earth mass planet with a 0ºC APST would be tall to extremely tall by Earth standards, and his body build muscular and stocky.
•  An intelligent life form from a 3.0 Earth mass planet with 60ºC APST, would be short and thin, perhaps not unlike a thin 4-6 year old Human child.
•  Should this creature have developed on a 0ºC APST planet, he would still be short, but his large volume to surface area would make him bulky and muscular.

 Skin pigmentation
As you may recall, earlier we considered the possibility that an aliens vision might extend a bit further into the violet or red portions of the spectrum, if he developed on a planet orbiting an intrinsically hotter or cooler star. Stellar parameters can leave their trademark in the  biotic community in other ways as well.

As one moves up the Main Sequence of stars, from spectral class K1 to F2, the bulk of the radiative energy emitted by each  class of star tends to shift from the red-orange to blue-white end of the visible spectrum. As the shift occurs, there is an increase in the percentage of ultraviolet radiation as the temperature of the star increases.

The ultraviolet radiation found in sunlight is deadly, it kills cells, causes burns, can cause skin cancer, can incapacitate.

Skin pigmentation is a protective adaptation against ultraviolet radiation. On our own planet, over the last 12,000 plus years, Man has become variated into three broad skin color groupings: the heavily pigmented Negro from equatorial regions, the Asian-Indian- Mediterranean stocks from around 30º latitude, and the lightly pigmented almost albino stocks from 45º-50º latitude.

In equatorial regions, the ultraviolet radiation influx is so great that unprotected flesh can experience serious sunburns, here adaptively has favored a heavy dark skin pigmentation.

At about 30 latitude, the relative solar radiation level has decreased 14%; in this area of high pressure and fewer clouds, Man’s skin pigmentation ranges from dark brown to olive.

Around 60 latitude, the solar radiation influx has decreased to about 50% of that at the equator. In these latitudes, marked by low pressure and greater cloud cover, Man developed blonde hair and a rosy white skin color.

If we matched a drop of paint with skin color matching every person on Earth, then mixed all these variously tinted drops together, the average color, average skin color would resemble  that of the Asian-Indian.

What would the average skin color be of an alien from one of our model worlds?
An intelligent aliens level of pigmentation and general skin color are derived from basically three factors.
1) The spectral class of the star his planet orbits.
2) The planet’s axial inclination, hence seasonal exposure to UV
3) The planet’s average percentage cloud cover

Diagram: Pigmentation in Exposed Flesh
.
Reading the Pigmentation diagram above, we see that very heavy, dark pigmentation would be found as an average condition on a small planet with 30% cloud cover which orbited a high UV producing F2 spectral class star. On the other hand, there would be little if any pressure to develop protective skin pigmentation on a large warm world with 80% cloud cover, orbiting a low UV K1 star.

Near the middle of this diagram, Earth’s average human pigmentation has fallen in the “medium” range (light brown, as seen in Indian and Asian populations) and is entered as a circle with a + inside, marking Earth’s 47% cloud cover, and the Sun – a G2 spectral class star.
Note: I’ve entered the typical racial pigmentations found on our own planet to serve as a guide\ for the am ount of relative need for protection. Alien bio-chemistry could as well produce gray, yellow orange or even chamelion like hues, or supplement skin color with thicker skin, extensive body hair, fur, micro hair-feathers, etc.

Computer Program: Generation of the Alien Physique (low resolution)
The following computer program produces an alien physique from the parameters discussed in this study. The basic morphological subprogram was extracted from the much longer and more complex program, AFARHOME, which I wrote around in North Star B.A.S.I.C. in 1980, for use on my Processor Technology, Sol computer.

Term descriptions:

! means, “Print”
!CHR$(11) tells the computer to “Clear the screen”
REM this statement and all others on a given line are ignored by the computer.
T alphabetic letters denote numerical data; i.e. “123”
T$ alphabetic letters with a dollar sign denote alphanumeric data; i.e., “stop, look and listen”
DIM statement creates the space required for alphanumeric data
1000, 1010 line numbers which are the road map routing followed by the computers logic circuitry.

I hope that in extracting this program from AFARHOME, that I didn’t introduce any ‘bugs’ to foul you up.

Alien Morphology subprogram

10 !CHR$(11)
500 DIM D$(30), D1$(30), D2$(30), D3$(30), D4$(40), D5$(30)
510 DIM D6$(30), D7$(30), D8$(30), D9$(30), E$(30), E1$(30)
520 DIM E2$(30), E3$(30), E4$(30), E5$(30), E6$(30), E7$(30)
530 DIM E8$(45), E9$(40), L$(30), L1$(30), L2$(30), L3$(30)
540 DIM L4$(30), L5$(30), L6$(30), L7$(30), L8$(30), L9$(30)
550 DIM M$(30), M1$(30), M2$(30)
1000 REM MORPHOLOGY PROGRAM
1010 !”What is the relative mass of your hypothetical planet?”
1020 !”Earth =1.0”
1030 !
1040 !”1) 0.25 2) 0.50 3) 1.0 4) 1.5 5) 2.0 6) 3.0”
1050 !
1060 INPUT “Choose mass by number”, H
1070 !CHR$(11)
1080 !”Choose an average planetary surface temperature.”
1090 !”Temperatures are in degrees Fahrenheit.”
1100 !
1110 !”1) 37 2) 59 3) 86 4) 113 5) 135
1120 !
1130 INPUT” Choose temperature by number.”, T
1140 !CHR$(11)
2000 REM ALIEN COMPOSITE SUBPROGRAM
2010 D$=” 0.…0”
2020 D1$=” 0www0”
2030 D2$=” oWWWo”
2040 D3$=” o….o
2050 D4$=” ……”
2060 D5$=” wwww”
2070 D6$=” WWW”
2080 D7$=” (o^V^o)”
2090 D8$=” (ovo)”
2100 D9$=” o(ovo)o”
2110 E$=” o(oVo)o”
2120 E1$=” o(O..O)o”
2130 E2$=” (O..O)”
2140 E3$=” (OVO)”
2150 E4$=” ( – )”
2160 E5$=” \ – /”
2170 E6$=” (-)”
2180 E7$=” \-/”
2190 E8$=” =>====o====(..^..}====o====<=”
2200 E9$=” =>===o===(.^.)===o===<=”
2210 L$=” (==|==)”
2220 L1$=” (=|=)”
2230 L2$=” | |”
2240 L3$=” | |”
2250 L4$=” | |”
2260 L5$=” (/ \)”
2270 L6$=” ( / \ )”
2280 L7$=” ( / \ )”
2290 L8$=” || ||”
2300 L9$=” | | | |”
2310 M$=” | | | |
2320 M1$=” /ooO) (Ooo\”
2330 M2$=” /oO) (Oo\
REM HAIR, EYES, NOSE, ½ FACE
9380 IF H>3 THEN 9390 ELSE 9430
9390 ON T GOTO 9400, 9410, 9410, 9420, 9420
9400 !D2$ \ D7$ \ GOTO 9540
9410 !D1$ \ D7$ \ GOTO 9540
9420 !D$ \ D7$ \ GOTO 9540
9430 IF H<5 THEN 9440 ELSE 9490
9440 ON T GOTO 9450, 9460, 9460, 9470, 9480
9450 !D$ \ E$ \ GOTO 9540
9460 ! D5$ \ D9$ \ GOTO 9540
9470 !D4$ \ D9$ \ GOTO 9540
9480 !D4$ \ D8$ \ GOTO 9540
9490 ON T GOTO 9500, 9510, 9510, 9520
9500 !D6$ \ E3$ \ GOTO 9540
9510 !D5$ \ E2$ \ GOTO 9540
9520 !D4$ \ E2$ \ GOTO9540
9530 !D4$ \ E1$
9540 REM JAW STRUCTURE
9550 ON T GOTO 9560, 9570, 9580, 9590
9560 !E4$ \ GOTO 9600
9570 !E5$ \ GOTO 9600
9580 !E6$ \ GOTO 9600
9590 !E7$
9600 REM SHOULDERS AND ARMS
9605 IF H<4 THEN 9610 ELSE 9620
9610 !E8$ \ GOTO 9630
9620 !E9$
9630 REM LUNG CAPACITY
9640 IF H=1 THEN 9650 ELSE 9680
9650 IF T<3 THEN 9960 ELSE 9670
9660 ! L$ \ GOTO 9680
9670 !L1$
9680 REM TORSO SEGMENTS
9685 ON H GOTO9690, 9720, 9750, 9790, 9820
9690 ON T GOTO 9700, 9700, 9710, 9710, 9710
9700 !LZ$ \ GOTO 9820
9710 !L3$ \ GOTO 9820
9720 ON T GOTO 9730, 9730, 9740, 9740, 9740
9730 !L2$ \ L2$ \ L2$ \ GOTO 9820
9740 !L3$ \ L3$ \ L3$ \ GOTO 9820
9750 ON T GOTO 9760, 9770, 9770, 9780, 9780
9760 ! L2$ \ L2$ \ GOTO 9820
9770 ! L3$ \ L3$ \ GOTO 9820
9780 ! L4$ \ L4$ \ GOTO 9820
9790 ON T GOTO 9800, 9800, 9810, 9810, 9810
9800 ! L3$ \ GOTO 9820
9810 ! L4$
9820 REM HIPS
9830 IF H < 4 THEN 9840 ELSE 9850
9840 ON T GOTO 9860, 9870, 9870, 9870, 9880
9850 ON T GOTO 9870, 9870, 9880, 9880, 9880
9860 ! L7$ \ GOTO 9890
9870 ! L6$ \ GOTO 9890
9880 ! L5$
9890 REM LEGS
9900 IF H=1 THEN 9910 ELSE 9940
9910 IF T < 3 THEN 9920 ELSE 9930
9920 !L9$ \ L9$ \ L9$ \ L9$ \ L9$ \ L9$ \ GOTO 10150
9930 !L8$ \ L8$ \ L8$ \ L8$ \ L8$ \ L8$ \ GOTO 10150
9940 IF H=2 THEN 9950 ELSE 9980
9950 IF T<3 THEN 9960 ELSE 9970
9960 ! L9$ \ L9$ \ L9$ \ L9$ \ L9$ \ GPTP 10150
9970 ! L8$ \ L8$ \ L8$ \ L8$ \ L8$ \ GOTO 10150
9980 IF H=3 THEN 9990 ELSE 10030
9990 ON TGOTO 10000,10010, 10010,10020, 10020
10000 ! M$ \ M$ \ M$ \ M$ \ GOTO 10150
10010 ! L9$ \ L9$ \ L9$ \ L9$ \ L9$ \ GOTO 10150
10020 ! L8$ \ L8$ \ L8$ \ L8$ \ GOTO 10150
10030 IF H = 4 THEN 10040 ELSE 10080
10040 ON TGOTO 10050,10060, 10060,10070, 10070
10050 ! M$ \ M$ \ M$ \ GOTO 10150
10060 ! L9$ \ L9$ \ L9$\ GOTO 10150
10070 ! L8$ \ L8$ \ L8$ \ GOTO 10150
10080 IF H=5 THEN 1090 ELSE 10120
10090 IF T<3 THEN 10100 ELSE 10110
10100 ! L9$ \ L9$ \ GOTO 10150
10110 ! L8$ \ L8$ \ GOTO 10150
10120 IF T<3 THEN 10130 ELSE 10140
10130 ! L9$ \ GOTO 10150
10140 ! L8$ \ GOTO 10150
10150 REM FEET
10160 IF H<5 10170 ELSE 10180
10170 ! M1$ \ GOTO 10200
10180 ! M2$
10190 INPUT “PRESS RETURN TO RERUN PROGRAM”
10200 ! CHR$(11)
10210 GOTO 1000
10220 END

Continued in Chapter 8: Into A New World

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Tuesday, February 7, 2012 · 12:10 AM

Chapter 6: Stellar Parameters

 Stars are originally formed from local condensations of interstellar gas and debris.
As the dust cloud contracts, it forms a relatively dense opaque sphere which is not yet hot enough for the occurrence of thermonuclear reactions.
The protostar continues to contract under its own increasing gravitation and begins to convert gravitational potential energy into heat and light. As time passes, the protostar continues to contract while its surface temperature increases. At a critical temperature, the atoms and ions within the interior of the star have begun moving fast enough to exert a balancing pressure against the weight of the overlying material. At this time, contraction ceases and a condition of near equilibrium begins.

The Main Sequence
Once the young star has reached equilibrium, it’s luminosity and surface temperature remain stable for a very long time. Stars having achieved this long-term stability are  said to be ‘Main Sequence stars’.

Please study the following, Hertzprung-Russel Diagram. As you look at the narrow sequence of stars that run across the H-R Diagram, from the upper left to the lower right, note that stellar luminosity and surface temperatures decrease incrementally between spectral class O through spectral class M.
As you move from upper left to lower right in the the diagram, the Main Sequence stars become cooler and less bright.
Its difficult to show in the diagram, but the color of the stars change as they become cooler, with the hottest stars being blueish, then white hot , then cooling to white-yellow, yellow, yellow-orange, orangish and finally, to small reddish stars.
On a clear night when you’ve been outdoorslooking at the stars, did you notice that some twinkle bluish, some white and some twinkle reddish? The color you saw is related to the star’s temperature and its stable period.

Residence on the Main Sequence
A star’s initial mass determines it’s length of stability, hence residence on the Main Sequence. See Table: Stellar Parameters below; and compare Mass (where p, our Sun, =1 for comparison) with a Stable Period (in billions of years) for the various stellar classes.

A large, hot, luminous star like a spectral class F2, uses its fuel rapidly, becoming unstable after maybe 3.47 billion years. A  smaller, cool, dimmer star, like the G9 spectral class uses its fuel much more slowly, giving it a stable period of 9.3 billion years. Other examples of this are;
•  A star of Spectral class B0 has a mass roughly 17 times that of our Sun, a surface temperature of about 20,000K and  a Luminosity 30,000  times greater than the Sun. This class of Main Sequence star radiates a very large amount of light and heat into space. Quickly using up its hydrogen fuel, it provides only an 8 million year period of stable energy output.
•  Stars of Spectral Class K0 have a Mass of only 0.74 and a Luminosity 0.28 of our Sun and a Surface Temperature of 4685K.      The K0 class of stars radiates relatively small amount of light and heat into space; slowly burning  their hydrogen fuel, they have a 28 billion year stable period of residence on the Main Sequence.

Lets assume that a star must remain stable for 3-1/2 billion years before intelligent, tool using life develops in its ecosphere. This assumption means that evolution occurred there considerably faster than it has on Earth; a process that could be accelerated by other stellar or planetary surface conditions.

A star of Spectral Class F2 has a 3.47 billion year residence on the Main Sequence, it is here that we will draw the upper limit for stellar luminosity and surface temperatures.

Table: Stellar Parameters

.

Table: Tidal Retardation and Stellar Spectral Class

Spectral   Class

<   G6

G7

G8

G9

APST   restrictions –
if any.

 All habitable APSTs may exist through G6 class stars. 45ºC  to 60ºC max. APST for G7 class stars. Only 45ºC and lower APST for G8  stars. 30ºC and lower for G9 class stars.
Spectral   Class K0 K1 K2   >

APST   restrictions –
if any.

 Only 15ºC and lower for K0 stars. Around   0ºC APST only for K1 stars. There is tidal retardation over the entire habitable APST range.

APST= The average planetary surface temperatures used in this study, ranging from oºC to 60ºC.

Between G7 and K1, only those planets with progressively cooler APST can be considered for this study. We will draw the lower habitable limit of stellar luminosity and surface temperature at spectral class K1.

Planetary models with average surface temperatures between 0°C and 60ºC can only exist in orbit around stars of spectral class,
F2 (upper limit), due to it sshort 3.47 billion year stable period and K1, below which the planet’s rotation is stopped.

Computing Sidereal Period and Orbital Radius
Early in this study, we learned that by starting with a planet’s average planetary surface temperature (APST), we could trace our way up through the atmosphere, adding on the Albedo energy losses, etc. and finally end up with the planet’s Solar Constant  at the top of the atmosphere.
We can now choose a Main Sequence star between Spectral Class F2 and K1, and by using the planet’s Solar Constant, determine the planet’s Sidereal Period (year length) and Orbital Radius (distance from star).
Please note that the Orbital Radius, Spectral Class and related Sidereal Period, are conditions which help create the Solar Constant on a model planet.

In the next graph, Computing Sidereal Period and Orbital Radius, I have eliminated the computations so that one need only read the graph in order to determine a planet’s sidereal period and orbital radius.

Let’s read through the graph once to see how it works:
Suppose that your planetary model has a Solar Constant of 1.5 Earth’s and that you wish to place this model in orbit around a F2 Spectral Class star:
Step 1.  Locate the 1.5 Earth equivalent Solar Constant on the bottom of the graph and read up until you intersect with the F4 Spectral Class curve.

Graph: Computing Sidereal Period and Orbital Radius

Step 2. From this intersection, read directly to the graph’s left margin and read the planet’s Orbital Radius, which in this example is 1.25 AU (25% further from the F4 star than we are from the Sun).
Step 3. Using a ruler or other straight edge, read from the 1.25 AU across the chart to the far right, until you intersect the curve on the Sidereal Period graph.
Step 4. From this intersection, drop a line straight down to the bottom of the graph and read the planets sidereal period (length of year relative to Earth), which in this case is 1.4 Earth years.
.
[Note, if you have turned to the graph above, Computing Sidereal Period and Orbital Radius, from the graph, Determining Solar Constants in Chapter 2, you will need to convert the ‘actual Solar Constant’ from cal/cm2 min into the ‘solar constant in Earth equivalents’ (where Earths normal =1) , by dividing the model planet’s Solar Constant by 1.97 cal/cm2 min. Usethe equation below, otherwise use the previous steps to determine  Sidereal Period and Orbital Radius.)
Conversion factor, if needed:  (2.95 cal/cm2 min)/ (1.97 cal/ cm2 min)= 1.5 as used in the example above.   ]

If you wish to do the calculations on your own, the equations are provided below,

R = /(L/Se)  and  R3= P2

R  = Orbital radius in Astronomical   Units (AU)
L  = Luminosity of the star relative to that of the Sun, so that  Š =1
Se= The model planets Solar Constant relative to Earth, so that  Ê = 1
P  = Sidereal Period, relative to Earth, so that Ê = 1

To convert orbital Radius from AU to miles, multiply

R (miles) = R(AU) * 93,000,000 miles/AU

 

Converting 24 Hour Earth Days to Alien Planet Days
In the previous example, we found that a planet with a Solar Constant of 1.5 (relative to the Sun), orbiting  a F4 Spectral Class star has a Sidereal Period 1.4 times as long as Earths, so that,

1.4 (sidereal period) * 365 days per Earth year = 511 Earth days per year for this particular model planet

During our discussion of planetary rotation in Chapter 2, we found that a planet’s mass is related to it’s rate of Rotation. See Table: Planetary Parameters, row ‘Rate of Rotation’, Chapter 2.  Note that a planet of 2.0 Earth mass has a 14.4 hour rate of rotation; it’s day is 9.6 hours shorter than our  24 hour day length on Earth.

The preceding equation gives the planet’s year length (Sidereal Period) in terms of Earth days. It is important to convert from Earth length days to alien planet length days, in order to gain a clearer perspective of the interaction between life forms and their duration of exposure to heat, cold, light, ultraviolet radiation, etc.

Consider the following examples;
•  If an American service worker spends 1-1/2 hours per day commuting to and from work, has a 1 hour lunch and 2 each 15      minute work breaks, he has spent 3 hours or 12.5% of an Earth standard 24 hour day, basically idle. If an alien worker living  on a 2.0 Earth mass planet with a 14.4 hour day, spent as much time commuting, eating lunch and on work break, those 3 hours we took would account for 20.6% of his ‘day’.
•  On a hot, arid desert, temperatures climb rapidly during the first hour after sunrise and begin to decline an hour before sunset.
On Earth, a desert inhabitant would have about a 10 hour exposure to extreme heat; however, a desert inhabitant on our model 2.0 Earth mass  planet, with its faster rate of rotation, would only have about a 5-1/4 hour exposure to extreme heat.
•  Survival, in a habitat  hostile to unadapted life forms, depends on the degree and length of exposure to the life limiting elements.

Converting from the number of ‘Earth Days per year’ to the number of ‘Alien Planet Days per ‘year’

Equation: Pa = (Pe*365 days*24 hours)/N

Pa = Sidereal Period in Alien days
Pe = Sidereal Period relative to Earth (where  Ê = 1)
N = Rate of rotation for the model ‘alien’ planet,  in hours.

From our previous example:
How many Alien days are there on a 2.0 Earth mass model planet which is orbiting a F4 star and having a 1.4 (w=1) Sidereal Period? Using the previous equation:

Pa = (1.4*365 days*24 hours)/14.5 hours

Pa = 845 Alien days is the length of  this model planet’s year
This model planet has a year length of 845 days, while each day is 14.5 hours long.
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Stellar Rotation
It’s currently felt that stars which are accompanied by a planetary system, have transferred most of their angular momentum to the planets.
In our own solar system, only 0.1% of the mass, but 98% of the angular momentum is tied up in the planets.
If the planets did not exist, the Sun would rotate once on its axis every 12 hours, instead of once every 25 days as it does.

When considering Main Sequence stars, there is a large decrease in the rotation rates between spectral classes O through spectral class A; however, the rate of rotation remains fairly constant between spectral classes F through S, this is thought to be the result of these cooler stars having transmitted their angular momentum to planetary systems in their domain.

 Table of Observed Stellar Rotation Rates

Planetary Systems
The space environment, around potentially habitable stars systems spectral class F – S, is likely to contain many of the same planetary orbiting bodies as are found in our Solar System. The general mass range of these bodies may include:  one or two stars, super planets, rocky planets, planetary satellites (moons), asteroids and comets; our system contains all these bodies except a super planet.

Alien intelligence may find their solar system containing a different numerical mix of orbiting masses, but if they ever develop a technical phase they would deduce the same laws regarding nature as we have.

Whether you have a 24 hour day and 365 day year, a G2 class star, 1.0 Earth mass planet with cool temperatures, or a 14.5 hour day and 845 day year, F4class  star, 2.0 Earth mass planet with warm temperatures is immaterial. The laws of physics and chemistry are the same on both and all planets.
Water will freeze or evaporate under similar conditions of temperature and pressure. Carbon will form with oxygen to make carbon dioxide, rain will soak into the soil and excess will run off in rivulets seeking to accumulate in lower areas, ie lakes or seas.
The poles on planet’s with low axial inclination will be much cooler than the equatorial regions.
Life will develop to make use of and extract stored energy in the environment.
During much of the planets habitable period there will be a Darwinian explosion in the number of life forms, representing greater diversity with occassional environmentally imposed fluctuations. Later, as the parent star becomes less stable, there will follow a several million year Post Darwinian collapse, extant life will become simpler in a habitat less capable of supporting life.

Continued in Chapter 7: Morphology of Intelligent Life

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Monday, January 16, 2012 · 12:15 AM

Chapter 5: Atmospheric Retention

At the beginning of this study, we  set the upper and lower limits for our planetary models at 0.25 and 3.0 Earth masses. The lower limit denoted a small planet which was in  the process of losing its water. The upper mass was the largest planet capable of losing its reducing atmosphere and still retain a potentially habitable average planetary surface temperature. Let now look at how these parameters were derived.

Exosphere Temperature
The outer most region of a planet’s atmosphere is called it’s ‘exosphere’. It is from the exosphere that molecules of atmospheric gasses, i.e.,, hydrogen, helium, water molecules, nitrogen and oxygen escape into space.

There are three basic factors at work in the exosphere which result in the loss of atmospheric gasses, these are:

  1. The planet’s gravity. Gravity is related to mass in such a way that the smaller a planet’s mass, the weaker its gravity. The weaker the gravity, the easier it is for a gas molecule to reach the planets escape velocity and become lost from the atmosphere. Compare the Planetary Mass, Gravity and Escape Velocities listed in the  previous, Table: Planetary Parameters Table, .
  2. The molecular weight of the gas is important: water  (H20) has a molecular weight of 18 and can escape from the atmosphere much more easily than oxygen (O2), which has a molecular weight of 32.
  3. The exosphere temperature: A cool exosphere temperature provides less of the energy required for gasses to escape.

Below is the method I used to determine a formula for calculating exosphere temperatures.

 Table: Comparative Cloud Cover & Exosphere Temperatures

Planet Exosphere Temperature ºK APSTºK Cloud Cover% Exosphere Temp/APST
Venus ~ 2500 ~ 426 100 5.8
Earth ~ 1650 ~ 293 ~ 47 5.6
Mars ~ 1200 ~ 223 ~ 10 5.4

From the table above, I divided each planet’s exosphere temperature by it’s APST providing the results listed in right most column, ‘Exosphere Temp/APST’. The average of these numbers, 5.6, was used as a rough constant, that when multiplied by the APST (ºK) of any of our planetary models, should give a close to actual exosphere temperature (ºK).

In order to calculate exosphere temperatures, first convert degrees Centigrade or degrees Fahrenheit into degrees Kelvin, then multiply your result by the constant, 5.6.

CONVERSIONS:

From Centigrade to Kelvin: APST ºC + 273 = APST ºK

From Fahrenheit to Kelvin: [(APST ºF – 32) * 5/9] + 273 = APST ºK

 Exosphere Temperature (K) = APST (K) * 5.6

By inserting each of our theoretical APST into the preceding equation we find the range of possible exosphere temperatures, seen below in the Table: Average Exosphere Temperature Range.

Table: Average Exosphere Temperature range

APST (ºC) 0 15 30 45 60
Exosphere Temperature (ºK) 1528 1613 1696 1780 1864

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Determining Atmospheric Gas Retention
In order to determine what gasses would be retained in the atmosphere for about 5-1/2 billion years, it was necessary to compute the Mean Square Root Molecular Velocity of an unknown gas. See Equation #1 below. Then using Equation #2, the molecular weight of the gas was found.

Equation #1 Equation #2
c = Ve/R M = 3rt/c²
c =  Mean square root molecular velocity
M =  Molecular weight of the gas
Ve =  Velocity of escape
r =  Constant: (8.314*10^7 erg/C mol)
R =  Retention factor
t =  Exosphere temperature C

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The Atmospheric Component Retention Table, seen below, shows what gasses are being retained or lost from the planet’s atmosphere. The separate, vertical red lines labeled, “Low Exo Temp” and “High Exo Temp” are the outside boundaries for the average exosphere temperatures previously determined, therefore encompass the 0ºC to 60ºC APST range used in this study.

The horizontal blue line labeled H2O (with a molecular weight of 18) is the upper limit for retaining water vapor in the atmosphere.

Where the  sloped, brown planetary lines remain below the molecular weight of 18, conditions favor the retention of water vapor, above 18 and the water will eventually lose its water. A 0.5 Earth mass planet (1/2 Earth mass) can be seen slowly losing its water at higher APSTs. The 0.25 Earth mass planet (1/4 Earth mass) is losing its water , therefore becoming more and more arid, across the habitable temperature range.

At lower APST, a 5.5 billion year old, 0.25 Earth mass planet may still have considerable water tied up in ice in mid to high latitudes. Life on these worlds may be very active along the seasonally melting permafrost regions. At higher temperatures there will be less water on the planet’s surface, because of the lack of substantial or any, ice caps.

Volcanism, geysers, etc., may be important in maintaining habitable zones. In any case, there will still be considerable water tied up chemically across the face of the planet. Please note that Mars with only 40% our hypothetical 0.25 Earth mass planet (1/10 Earth mass) is thought to have polar accumulations of frozen water and frozen CO2  (carbon dioxide). [Written in the 1980s – lfp]

We should view the small 0.25 Earth mass planet as a planet that is slowly drying up. It did not have much water to begin with (relatively speaking) and after 5-1/2 billion years it has considerably less. We should also realize that our calculations have been aimed at a 5-1/2 billion  year residency of potentially loseable gasses. If the planet were, lets say, 3-1/2 billion years old, there would be more water available. A large asteroid or comet strike every billion years or so would bring about more volcanic activity and release meaningful quantities of H2O (water) from the planet’s crust, being favorable for the creation of life, yet a hazard to existent life.

All of the planets in this study can be seen to have retained oxygen in their atmosphere. (molecular weight 32). Note, however, that the large, 3.0 Earth mass, planet has barely lost its primal atmosphere envelope of hydrogen.

Continued in Chapter 6: Stellar Parameters

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Tuesday, January 3, 2012 · 12:46 AM

Chapter 4: Atmospheric Circulation

The next variable we’ll consider in determining the general climate on a model planet, is it’s atmospheric circulation system.

The surface wind systems with their distribution of atmospherically absorbed solar energy and powers of precipitation and evaporation, are immensely important in creating climate and determining basic direction in which biological adaptations must be made.

At the beginning of this section, I should point out that my use of the terms, ‘tropic’ and ‘subtropic’ are not meant to suggest jungle or climatic conditions similar to those found on Earth, but as geographic locations and ‘conditions relative’ to the given average planetary surface temperature.

The tropic region is that area extending about 20º latitude on either side of the point perpendicular to the planet’s parent star, for most of the models, this is above or somewhat near the equator.

The average temperature of tropic (usually, but not always equatorial) regions on the planet models used herein, extend between 41ºF and 151ºF, depending on the selected model.

The sub tropic region, is an area about 25º latitude above and below the point perpendicular to the planet’s sun. Let’s consider the basic planetary climatic zones, seen in the illustration below.

The tropical, subtropical, temperate and frost zones on our model planets may be nearly stationary and relatively tranquil, as in Figure A; or they may move up and down across the latitudes with specific seasons, seen in Figure B; or they may move across longitudes with sweeping change, as in Figure C.

Air movement
Air close to the ground in the tropic zone absorbs ‘relatively’ large amounts of heat. As this occurs, the capacity of the air to hold moisture increases and the warm mass of air begins to rise in the atmosphere. The rising air is replaced by cooler air as it moves onto progressively cooler regions.  As the warm air cools, it looses it’s ability to carry moisture, where upon the excess moisture is lost through precipitation.

The cooling air mass continues to move away from the tropic zone toward those areas which receive a lesser amount of seasonal sunlight/ As the air moves, it further cools and begins to sink.

In order to gain a background understanding of atmospheric circulation we’ll now discuss only those planetary models with relatively low angles of axial inclination.

Around 35º latitude, the relatively cool and drier air finally reaches the ground and creates a general band of high pressure; from this point, the now cooler air begins to move back toward the tropic zone.

Cool air does not carry much moisture, so as the cool air mass moves from about 35º latitude to 20º latitude, it will be crossing relatively arid terrain. Since these latitudes still receive about 80% of the sunlight available in the tropics, this zone will be relatively hot, as well as dry. This portion of the atmospheric circulation system can be seen in the associated illustration, Tropic and Sub tropic Zone Circulation.

On the whole, the circulation system of the tropic and sub tropic zones will be quite large and fairly steady, except on worlds with high axial inclination,

Biologically, conditions in the tropic zone depend on temperatures and the availability of water.

On planets with low axial inclination and low to mid range APST (about 0ºC-30ºC), I suspect we would find something between temperate and steamy tropical forests as temperatures were elevated. Between an APST of 45ºC and extending up toward 60ºC, I believe the tropical forest would break down to be replaced by simpler plant communities with smaller individuals. Under these conditions, hot temperatures become a limiting factor in much the same way as cold temperatures limit growth in Earth’s tundra.

Around 50º to 60º latitude, on either side of the central tropic zone, there is a low pressure area. This region is cooler than the tropic low since it receives only about one half the solar energy. Being cooler, this mid latitude area is less humid and receives less precipitation.

The asterisks at 1.0 in the above graph, Relative Precipitation and Latitude axis, indicates the average precipitation level for the model world. Once the average precipitation and evaporation rate has been calculated a good model can be made for precipitation.

The following precipitation table was computed using data from the table in Chapter 3: Climatic Factors, Table: Data for Computing precipitation and Evaporation Rates used in either the associated equation or the BASIC computer program.

Table:  Average Inches of Precipitation and Evaporation for Planets with the given Mass and APST

Planetary Mass   Ê = 1
   APST ↓ 0.25 0.5 1.0 1.5 2.0 3.0
APST ºC 0ºC 55.1 50.4 41.7 35.2 29.5 18.2
15ºC 56.5 49.6 41.2 34.6 28.6 15.9
30ºC 55.8 49.6 40.6 33.6 27.4 13.0
45ºC 55.2 48.7 40.8 31.9 25.0 7.8
60ºC 55.0 48.4 38.9 30.4 19.2 5.2

In order to see if the preceding table had relevancy, I also ran calculations for Earth, where the averages are fairly well known, see following table:

Table: Average Inches of PPT & Evaporation on an Earth Mass Planet with 24 Hr Rate of Rotation

APST ºC 0 15 30 45 60
Inches Precipitation 41.7 42.07 40.6 38.9

Earth, with al 20ºC APST, has an actual  average annual precipitation rate of 40 inches.  The theoretical (calculated) Earth mass planet with 20ºC APST and 24 hour rate of rotation  has 41.6 inches of precipitation, a 4% difference between the actual and theoretical. Graph the above table (using the Chapter 3- Table: Cosine of planetary latitudes)

Although the theoretical precipitation rate works out well for an Earth type planet, meaningful equation results seem to degenerate as we approach the much smaller 0.25 Ê mass or the larger 3.0 Ê mass planets.

On the 0.25 Earth mass planet: At 0ºC to 15ºC there is a fairly small habitable zone which may indeed receive the theoretical amount of precipitation; however, most of what water exists on the planet will be locked up as ice in higher latitudes. Also, because there is a small water to land ratio, there is a very large area which will be arid-cool arid and cold arid.

In the 30ºC to 60ºC range, we’d find the higher latitude ice and frost caps either gone or greatly diminished. This would not lead to larger bodies of liquid water. The 0.25 Earth mass planet is a planet losing its moisture. The surface gravity is such that at higher temperatures, water molecules in the atmosphere simply drift out into space, resulting in a planet that is slowly drying. Therefore, in the higher APST range, I would suspect the precipitation and evaporation figures to break down. Several billion year old planets of this small size and high temperature would have relatively dry atmospheres.

On the large 3.0 Earth mass planets there maybe only small land masses, perhaps only island chains as opposed to ‘continents’. Warm moist ocean air might not move out onto large cool land masses.

At 0ºC to 15ºC, there would exist in the north and south latitudes, very large ice caps. Under cooler conditions the oceans would have reduced depth and the island land masses may have expanded to form small continents. This scenario would tend to increase the precipitation level for those areas, above the data given in the Precipitation and Evaporation table.

In the 30ºC to 60ºC APST range, we would find the ice caps diminishing to frost caps and finally entirely absent. As the APST increases, the atmosphere would become more and more saturated with moisture. Instead of true precipitation, we may find states of continual condensation occurring on terrestrial objects, especially at night and in latitudes experiencing change of season. Humidity would be extreme.

Wind deflection
Because all of the planet models rotate on their axis, we can expect wind systems to be deflected at various latitudes on either side of the tropic zone. The basic global air circulation for models, with a low to mid range axial inclination may be illustrated as follows.

As we study the Basic Global Circulation model above and recall the concepts derived from Tropic and Sub tropic Zone Circulation, illustration, page 21 and Relative Precipitation and Latitude graph, page 21, we are able to predict some interesting bits of information about continental climates.

Looking at the Subtropical Highs, we see the winds have a tendency to move from east to west as they return to the low pressure area in the tropic zone. This moving air mass is relatively cool and dry, and as previously mentioned, the area of the planet’s surface crossed will tend to be warm and arid, relative to the APST and the average planetary precipitation rate. The biotic community, which extends across these bands of high pressure depend on the APST, so that on worlds with an

APST  0ºC: The planet may carry cold/dry adaptive, coniferous forest type vegetation

APST  30ºC: Zone may be a hot desert.

APST 60ºC: Plant life is sparse and terrestrial animal life nocturnally active.

Local Climates
At any latitude, where high mountain ranges are situated perpendicular to the prevailing winds, we could expect higher moisture on the windward side and more arid conditions on the lee side.

On planetary models with some degree of axial inclination, that hemisphere undergoing Spring would have its land masses heating up faster than the oceans. This results in a low pressure system developing over the land and a high pressure system developing over the adjacent ocean. Conversely, in the Fall, the land would cool faster than the ocean and the high and low pressure systems would be reversed.

Water has a greater capacity to hold heat than does soil. Therefore the temperature variation between land and ocean would remain more stable in  the equatorial region that at higher latitudes on worlds with much free surface water.

Inland areas of continents have a far greater annual variation in temperature than coastal areas of the same latitude.

The planet’s surface temperature range
Planets with small axial inclinations have small variations in seasonal temperatures. As the axial inclination increases, the total range of temperatures for each latitude expands.

Model planet A, at left, has  0º axial inclination. An observer at 0º latitude would note his Sun rises to a point directly overhead every day and that the average temperatures through out the year is, let’s say, 81ºF.

Model B has a 15º axial inclination. An observer at 15º N will note that the sun is directly overhead at noon during the summer and that his summer average  temperature is perhaps 81ºF. Half a year later, the Sun has apparently moved to a point 15º below the equator and is now 30º lower in the sky to our observer. Recording his average Winter temperature of 70ºF, the observer notes that there is a 11ºF difference between his Summer and Winter temperatures averages.

Model C has a 45º axial inclination. This time, our observer is located at 45º N latitude. He notices the sun directly over head at noon and a temperature of 81ºF during the summer. Half a year later, the Sun has moved to a point 45º below the equator and is now 90º lower in the sky to the observer. At noon during the winter, the Sun will rise to a point where it just peeks over the southern horizon and the average temperature will be about -25ºF,

For the sake of comparison and to develop a better understanding of axial inclination and the subsequent temperature range, see the following table:

Table: Approximate Change in Temperature Range  (from the concept explanation above)

     AXIAL    INCLINATION SUMMER      ºF WINTER   ºF TEMPERATURE RANGE ºF
        0º     81      81        0
       15º     81      70        11
       45º     81     -25       106
For a planet of 1.0 Earth mass and 20ºC APST (Earth like); the axial inclination has been varied in the table to show simplified temperature effects. Our imaginary observer is located at a latitude above the equator which is equal to the planets axial inclination. For any given location on a planet, the greater the axial inclination, the greater the temperature range for that location and therefore, the greater the variation in its seasonal climate.
The chart shows, the greater the axial inclination, the more pronounced are the ‘seasons’ of the year.
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Thunderstorms
All the planets whose mass and APST fall within the parameters of this study will have thunderstorms, with possible exception of the 0.25 Earth mass planet. The ingredients necessary for thunderstorm development are unstable warm air and humidity. These conditions exist in at least some latitudes on all the other, larger habitable planets. About the only area that would not be at least occasionally affected by thunderstorm activity would be the ice caps and other extensive desert (arid) regions

Continued in Chapter 5: Atmospheric Retention

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Wednesday, December 21, 2011 · 1:57 AM

Chapter 3: Climatic Factors

Attempting to determine the basic climatic conditions for our model planets, we will take into account several major variables. We will attempt to treat some of these variables in order to develop an insight into general planetary climatology. You should keep in mind that the approach taken in the survey is a combination of intuition and empiricism and that even current attempts to calculate mean annual temperatures for Earth (mid to late 1960s) have not been highly successful.

Axial Inclination
Axial inclination refers to the number of degrees which a planet’s equator is tilted from its orbital plane.

Since all of the planets in our Solar System display axial inclination, we may theorize that whatever the process leading to its development here, perhaps exists universally. However, since the process isn’t understood, we’ll consider various degrees of axial inclination to develop an understanding of their general effect on a planet’s surface temperature.

Axial inclination, near 0º
On a planet with 0º or near 0º axial inclination, the temperature, precipitation rate and length of day would not vary appreciably in any one spot throughout the year, assuming a nearly circular orbit. circular.Because the planet has no tilt, there  would be no seasonal change as the year progresses. At any point on the planet’s surface, the  prevailing conditions in January would be the same as  in July. Low latitudes, near the equator, would experience the planets perpetual summer temperatures. High latitudes, nearer the poles would exist in a relative condition of winter with low illumination. On either side of the equatorial summer zone, there would exist temperatures we may classify as relatively spring like. The next zone would be fall like, with temperatures declining as one approached the high latitude winter zone.

Proceeding from the equator toward either pole, you would almost imperceptibly move across the planet’s surface temperature gradients, from relatively hot, to relatively cold.

Many plant species on Earth require a certain number of days with frost, a particular number of hours sunlight or some other abiotic factor to trigger seasonal growth. On worlds with 0º or very low axial inclination, plant life would have made other adaptations to the essentially non varying climate at their latitude. We might expect more sensitive biological triggers and a greater number of species which were perennials and fewer annuals.

Axial inclination approaching 90º
Worlds with axial inclinations approaching 90º would experience some really exciting seasonal climatic variation.

As the planet orbited its parent star, it would alternately have one of its poles bathed in summer sunlight for a quarter year, have a quarter in semi dark winter. Between the long hot polar summer cold winter cycles, the lower latitudes would gradually shift into a regular day and night cycle. The day and night cycle on this model would be complex, with the polar regions growing tropically warm in their seasonal summer and declining to Arctic cold in their seasonal winter.

Note from the preceding diagram that , the planets south polar region is experiencing summer. A few months later having orbited to position B, the polar regions are now located at a point approximately 90º from the sun, therefore are experiencing conditions similar to those at Earth’s poles. Note also that in position A, the “spring and fall” moderate temperature zones on the illuminated side of the hemisphere do not experience night. In these locations, the sun would simply circle in the sky. But it would not set As the planet orbits to position B, the spring  and fall temperature zones acquire a day and night cycle.

To a person standing on the illuminated hemisphere in planetary position A, the sun would appear to circle in the sky, but as the weeks passed, the apparent circle would spiral closer to the horizon. At some point midway between points A and B, the sun would dip below the horizon for a period of sunset, then it rise again. Approaching position B, the sun would set and nights would become longer. At position B, the sun would rise on one side of the horizon and set on the other, visually similar to what we experience.

As the planet orbited toward position C, the sun would  be seen to rise lower and lower in the sky, the days would shorten and temperatures. At position C, an observer at the south pole would be in several months of cold darkness. Southern latitudes would be in s state of extended twilight. Northern latitudes would be basking under extended periods of continuous daylight. At the same time, the north polar region would be baking in a summer season under overhead tropical sunlight.

Note that between location A and C, the poles experiencing summer and winter have reversed.

If this planet had an APST of 68ºF (20ºC) then a large percentage of the planet’s surface would experience a temperature range from between 81ºF to -25ºF. I would more or less expect tundra type terrain and vegetation on either side of the equator and vegetation specialized for hot and cold temperatures in higher latitudes.

Should such a planet exist in the ecosphere of a F class star, it would have a long year and therefore longer seasons for growth, before dormancy. Migration might play a major influence amongst larger life forms. If the planet orbited a relatively small cool class K star the year would be short and the growing season reduced.

Intermediate axial inclinations
Climatic factors arising on planets with intermediate axial inclination would vary according to the level of inclination. Planets with axial inclinations of 10º-15º will have milder seasonal temperature variations than planets with larger inclinations.

Those of us living in the mid latitudes on Earth (my 1980-2005 home is roughly on 45º33’ north latitude) can attest to the seasonal climatological effects of Earths 23½º axial inclination.

A mid latitude location on a planet with an APST of 20ºC and a 40º-60º axial inclination would be subjected to a steamy tropical summer and a frigid Arctic winter. On small to mid size planets with moderate inclinations, plant life would have developed highly protective tissues against the relative cold and heat. Desiccation and starvation  would be major biological problems.

Warm vs. Cold-bloodedness
Axial inclination and APST are two very important variables in broadly determining whether intelligent life on our model planets are warm or cold-blooded.

Basically, the difference between being ‘cold blooded’ or ‘warm blooded’ is that the former life forms are dependant on external temperatures while the latter have developed mechanisms to maintain internal temperatures under a wide range of external temperatures.

Persistent wide variability, periodic extreme oscillations and ‘cold’ or ‘hot’ are conditions conductive to the development of warm ‘bloodedness’. On the contrary, mild and seasonal temperature changes in a warm climate (not hot) are favorable to cold ‘bloodedness’.

It takes more biological equipment to be warm-blooded than cold-blooded; however, the extra activity gained in a hostile environment, apparently make the investment worthwhile.

I’ve worked out the following graphic to demonstrate the gross conditions where I believe we might find the development either cold or warm-blooded life forms.

In the upper portion of the graph, hot temperatures tend to be a limiting factor for cold-blooded dominant life forms. Low and to the left, it is general cold that limits cold-blooded expansion and-or probabilities. Looking up and to the right, we see that warm ‘bloodedness’ is favored as the  planets axial inclination rises, since this increases the summer high and drops the winter low temperature average for each latitude.

Although warm-blooded dominant life forms could exist on all the planetary models represented in the graph, cold blooded dominant life would probably be found on planets whose general climatic scheme was delineated by the green hashed area.

Planetary energy balance
In order to determine evaporation rates, we need to start with the total available solar radiation, make the necessary subtraction for albedo, etc. and thereby find the planets working energy balance.

We’ll start at the top of the planet’s atmosphere with the solar constant, a ‘constant’ because it varies little over a long period of time.

Coming down through the atmosphere, the first quantity of energy we subtract from the solar constant is the albedo, this amount is reflected back into space by atmospheric reflection (from the cloud cover). The remaining energy  is almost entirely used to heat the planet’s surface and to circulate the atmosphere.

Since atmospheric surface pressure is related to atmospheric density, the ratio between percent energy absorbed by our atmosphere and the surface pressure were used to determine the percent energy absorbed by the atmospheres of our model planets.

In the following table, the percent energy absorbed from the incoming radiation by the atmosphere is shown related to the corresponding planets mass.

Mass of planet ,  Ê = 1 0.25 .50 1.0 1.5 2.0 3.0
Percent energy absorbed 7 12 17 20 22 25

Having  reduced the solar constant by subtracting out the albedo and the energy absorbed by the atmosphere, what we have left is the radiant energy actually reaching the planet’s surface. Of this energy, some is lost as long wave radiation and some is reflected. When water or ground moisture is available, nearly all the remaining energy is used in evaporation.

Computing precipitation and evaporation
It’s been calculated that the average evaporation and precipitation rate for Earth is 100 cm (40 inches) per year. However, this is merely an average, because there is a sizeable difference in this rate over land and sea. The oceans have a precipitation rate close to 111 cm. (44 inches) and an evaporation rate of 120 cm (48 in), with the difference being returned to the oceans by river flow.

On land, the average precipitation rate is 71 cm (28 inches) per year with about 24 cm (10 inches) lost by river discharge.

The average evaporation rate for land is misleading because it takes into account a large portion of the land surface which contributes little to the figure, for example, tundra, icecaps, deserts and mountains. When these areas are taken into account, we find that the balance of the land receives about 100 cm (40 in) per year, the global average.

On a global scale, total evaporation equals total precipitation, or “what goes up must come down”. The following equation may be used to calculate precipitation or evaporation rates for our model planets:

Average annual Planetary Precipitation (cm) = [(1-(A+a)) *(0.29d)* (0.4E((/R3*8760)/Z)]/H

Conversions: The precipitation rate in cm/2.5 = the precipitation rate in inches.

Factors used in the Precipitation computation See the required data in Table: Data for computing precipitation and evaporation rates, below.

A   = Percent energy absorbed by the planet’s atmosphere.
a   = Percent albedo loss, See below, Table: Data for computing precipitation and evaporation rates.
d   = Planetary rate of rotation in minutes.
E   = See Determining Solar Constants (read in cal/cm² min), Chapter 2.
R   = See Orbital Radius, See Chapter 2.
H   = Latent Heat of vaporization.
Z   = See Planetary Rate of Rotation (in hours).

The following Table: Data for Computing Precipitation and Evaporation Rates, provides the data required to calculate average precipitation and evaporation for the model planets:

Table : Data for computing precipitation and evaporation rates

M Mass  w = 1 0.25 0.50 1.0 1.5 2.0 3.0    
A1 % Energy absorbed by the Planets Atmosphere 0.07 0.12 0.17 0.20 0.22 0.25 0.31 0.34
A2 % Albedo loss 0ºC 0.20 0.22 0.30 0.36 0.42 0.54    
15ºC 0.22 0.26 0.33 0.39 0.45 0.57    
30ºC 0.26 0.30 0.36 0.42 0.48 0.61    
45ºC 0.30 0.33 0.38 0.46 .052 0.61 = x  
60ºC 0.33 0.36 0.42 0.49 0.59 0.61   = x
D Rate of Rotation (minutes) 1380 1200 1020 900 870 780    
Z Rate of Rotation (hours) 23 20 17 15 14.5 13    
E Solar Constant(cal/cm² min) 0ºC 1.34 1.4 1.58 1.7 1.88 2.36    
15ºC 1.58 1.62 1.82 2.0 2.22 2.4    
30ºC 1.8 1.9 2.08 2.3 2.6 2.8    
45ºC 2.06 2.16 2.38 2.72 3.0 3.3    
60ºC 2.34 2.48 2.7 3.08 3.48 3.92    
H Latent Heat of Vaporization of Water (cal/gm) 0ºC 595    
15ºC 588    
30ºC 580    
45ºC 571    
60ºC 563    

Left column labels M, A, A2, etc. are computer variable names used in the following computer program.

x = Seen at right in the table show the percent energy absorbed at 100% cloud cover, the last two 61% albedo loss only.

Using data from, Table: Data for Computing Precipitation and Evaporation Rates, you may compute the average precipitation and evaporation rates with the following B.A.S.I.C. language program.

Line Number Northstar B.A.S.I.C.
10 REM   CALCULATE INCHES PRECIPITATION FOR PLANETS
20 !CHRS$(11)
30 INPUT   “Mass of planet ?”, M
40 INPUT   “APST ?”, W
50 INPUT   “% Energy absorbed by atmosphere ?”, A1
60 INPUT   “% albedo loss ?”, A2
70 INPUT   “Rate of Rotation  (in minutes) ?”, D
80 INPUT   “Planets Solar Constant ?”, E
90 INPUT   “Rate of rotation (in hours) ?”, Z
100 INPUT   “Latent Heat of Vaporization (water) ?”, H
110 REM   L=SPECTORAL CLASS-G0-STAR LUMINOSITY
120 L=1.04
130 REM   CALCULATE ORBITAL RADIUS RELATIVE TO EARTH
140 E1=E/1.97
150 R1+L/E1
160 R2=SQRT(R1)
170 R3=R2*R2*R2
180 REM   R4=RELATIVE SIDEREAL PERIOD
190 R4=SQRT(R3)
200 REM   PRECIPITATION EQUATION IN CENTIMETERS PPT.
210 P1=[1-(A1+A2)]*(0.29*D)*[0.4*E(R4*8760/Z)]/H
220 REM   CONVERT CENTIMETERS PPT TO INCHES PPT
230 P2=P1/2.5
240 !   ”MASS PLANET”, M
250 !   “APST”, W
260 !   “INCHES PPT”, P2
270 INPUT   “Do calculations again ? Y or N”, Q$
280 IF   Q$=”Y” THEN 20, ELSE 290
290 END

If you multiply the planet’s average precipitation or evaporation rate by the cosine of the planet’s latitude you’ll be able to roughly determine the precipitation or evaporation for the chosen latitude.

Table: Cosine of planetary latitudes

Latitude 0º 10º 20º 30º 40º 50º 60º 70º 80º 90º
Cosine 1.0 0.984 0.939 0.866 0.766 0.642 0.500 0.342 0.173 0

The preceding method of determining precipitation rates over the planet’s surface will be modified in the next chapter.

Continued in Chapter 4: Atmospheric Circulation

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Tuesday, December 6, 2011 · 1:05 AM

Chapter 2: Average Planetary Surface Temperature (APST)

The Average Planetary Surface Temperature (APST) range used in this study was taken in part from the wide limits found amongst life forms on Earth. The range is 0ºC to 60ºC for the vast majority of the Plant and Animal Kingdom. Below the freezing point of water, 0º C, as ice,  water is no longer a dispersion medium for chemical activity, and above 60°C, protein coagulates.

It should be realized that on Earth, a few organisms that have adapted to extreme temperatures that are much higher or lower than the average. These organisms already had a several billion year evolutionary history of thriving in more normal temperature environments, before slowly adapting to these more extreme, hostile conditions.

Temperature Discussion
Temperature means “intensity of heat” and the average amount of heat in a body is the average kinetic energy of the molecules of which that body is composed.

In the plant kingdom, temperature and precipitation are the  major climatic factors determining a species range. Temperature influence the plant activities of water absorption, transpiration, germination, growth, photosynthesis and reproduction.

The effects of high temperature on plants are: desiccation and basically, starvation, since the rate of respiration becomes so high that food consumption exceeds production by photosynthesis.

As temperatures rise, the rate of chemical reactions increase, so that with each, approximately 10ºC increase in temperature, there is a 100% rise in the rate of chemical reaction. This occurs because the increase in temperature causes greater molecular activity and more molecules reach the energy plateau necessary for their specific reaction.

Enzyme catalyzed reactions increase in rate until about 50ºC, above this the enzymes are rapidly inactivated and destroyed by heat denaturalization. Protein extracted from living tissue coagulates around 60ºC, but some thermophilic bacteria have adapted to temperatures as high as 75ºC.

Most of our food crops require a temperature between 10ºC and 30ºC during their growing season. Where as the overall majority of plants cease functioning below 0ºC, many are capable of short-term survival at exposures down to -50ºC to -62ºC. At low temperatures (approaching 0ºC) plants cease to  be metabolically active, because internal temperatures are similar to external temperatures; the result being a greatly reduced enzyme activity and the freezing of water.

As can be seen, temperature plays a strong role in the biology’s of Earth. The same basic chemical building blocks, ie, carbon, nitrogen, water, sulfur, lead, iron, etc, exist on planets beyond our solar system. Alien life forms will be circulating the elements from the natural environment through their bodies in a way not necessarily identical to us, but in similar ways for their own nutritive needs.

Because plants cease to function below 0ºC, this will be the lower Average Planetary Surface Temperature (APST) used in this study, because protein coagulates at or around 60ºC, this will be the high APST used in this study.

Table: Intuitive Comparisons of Planetary Surface Temperatures

0°C 32°F Average surface temp on Mars -67°F with an overall range of -207°F to 80°F. The annual mean temperature at the North Pole is -40°F in winter and 32°F in summer.
15°C 59°F 59°F is Earth’s average temperature.  Los Angeles averages 66°F, with a seasonal low of about 45°F to highs around 90°F.
30°C 86°F HUMID: Manila,   Philippines – mean annual relative humidity 73.8%, (82% RH during rainy season, about the maximum moisture that the atmosphere can hold, with an average temperature of 82°F;  88°F to  93°F daytime high temperatures are common.
Bangkok, Thailand – mean annual RH 80%, with an average temperature of 82°F; 88°F to 92°F daytime highs common. These places experience extreme humidity during their rainy seasons combined with warmth giving the feel of a lukewarm sauna.  [Wet planet with 30°C ASPT-think ‘lukewarm sauna’]
30°C 86°F DRY: The average annual temperature for the Sahara desert is 86°F (30°C) with an   average humidity of 25%. Hot dry air and soil.
Dallol, Ethiopia, is the warmest   place on earth with an average yearly ambient surface air temperature   of 34°C = 93°F.  [Dry planet with 30°C ASPT-think, ‘typical hot, arid desert’]
45°C 113°F In July the Sahara desert reaches temperatures of 113°F to 122°F degrees; with the sand reaching 170°F, and rocks 100-110°F. [Dry planet: Think, ‘extreme desert conditions’. Wet planet: Think, ‘extremely dangerous heat and humidity’].
60°C 140°F Earth record   temperatures: Lut Desert of   Iran, 159°F (2005), El Azizia, Libya, 136°F (1922); Death Valley, California, 34°F (1913).

Formula for converting from °C to °F:
(°C x 9/5) + 32 = °F

Percentage Cloud Cover
Having chosen the APST limits for our model planets, it is necessary to determine what environmental conditions would create such temperatures. The first problem I encountered was the need to have a correlation between APST, planetary mass and cloud cover. I intuitively derived the multi axis graph entitled, Cloud Cover Determination, seen below.

Cloud Cover Determination Diagram

Read the Cloud Cover Determination Diagram, proceed as follows: 1) Choose a planetary mass from the bottom axis and an APST from the left axis, 2) Read up from the selected mass to intersect with the selected APST. 3) At the mass-APST intersection read to the upper right to the associated Percent Cloud Cover scale. Example: A planetary mass of 0.5 (Ê = 1) and APST of 15ºC would be found with approximately a 30% cloud cover.

The Cloud Cover Determination chart is important, because ‘cloud cover’ is a factor in the determination of the amount of sunlight that reaches  the planet’s surface and how much is reflected by clouds, back into space.

 In order to make the Cloud Cover Determination Diagram, I compared the APST, cloud cover and mass of Venus and Mars with Earth. It became apparent that average planetary cloud cover is correlated with two major parameters: planetary mass and APST. In the case of Venus, a planet with nearly the mass of Earth, but with a much higher APST, the cloud cover grew to 100% transforming it from optically thin to optically dense. The dense cloud cover further increased the APST through the greenhouse effect, which in turn vaporized yet more material and created a still denser atmosphere.

By considering the crystallization of albite as an example of the process leading to the formation of water, and saying that an equal percentage of the mineral composing each planet’s crustal material, then the amount of water released from the crust of the largest planet would be about twelve times greater than the water released from the crust of the smallest planet. Note that the planetary mass range in this study extends from 0.25 to 3.0 Earth masses.

Since the surface area of the largest planet is only three times as great as the smallest, yet carries twelve times more water. It is clear that the surface of the largest planet is nearly covered with water, while the smallest planet is covered primarily by dry land.

As the size of the planet increases from 0.25 to 3.0 Earth masses, the percentage of the  planet’s surface covered by water increases. At any given average planetary surface temperature, between 0ºC and 60ºC, there would be more total evaporation occurring from the surface of a large planet than from the surface of a small planet. See diagram below.

Comparing Several Features of Large and Small Habitable Planets
For the purpose of this study, and to gain a relative insight into planet’s ecology under varying conditions, I have with some thought, assigned each of the following planetary models with a reasonable percentage surface exposed to land and water.

Land Mass vs. Water Ratio table

Planetary   Mass, Ê = 1 0.25 0.50 1.0 1.5 2.0 3.0
Percent Land 95 60 30 22 15 5
Percent   Water 5 40 70 78 85 95

The  ratios given in the previous table would be variable, since on cold planets, water would be frozen out to form thick expansive polar icecaps; while on relatively warmer planets, there would be little or no ice, hence less surface area in dry land.  [Note: Mars has a mass of 0.1 Earth, only 40% the size of the smallest planet used in this study, and would therefore expected to have very little surface water. Being further from the Sun, most of the water that has not evaporated from the planet’s atmosphere would be found frozen in polar sheets; leaving a very large dry land to (frozen) water surface ratio – as we’ve found.]

On a large planet, the atmosphere is quite dense near the surface, but loses density rapidly with elevation. On small planets, the atmosphere is less dense near the surface and trails of more gradually with increased elevation.

These factors affect the percentage cloud cover in such a way that when comparing a larger and smaller planet of similar average planetary surface temperature; the larger planet would have a larger, thicker cloud cover, while the smaller planet would have a smaller, thinner cloud cover.

On any of our planetary models, the warmer the APST, the greater the percentage cloud cover. Naturally, the warmer it is, the greater the evaporation, the more moisture the air can carry and the greater the cloud cover.

Planetary Parameters Table

Planetary Mass, Ê = 1 0.25 0.5 1.0 1.5 2.0 3.0
Planetary Mass, Nx10^27 grams 1.49 2.98 5.97 8.96 11.93 17.9
Surface Gravity, Ê = 1 0.52 0.69 1.0 1.23 1.36 1.69
Surface Area, Ê = 1 0.46 0.68 1.0 1.2 1.42 1.70
Surface Area, Nx10^8 mi. 0.93 1.41 2.02 2.41 2.86 3.43
Circumference, Ê = 1 0.67 0.83 1.0 1.1 1.2 1.3
Radius in miles 2730 3360 4020 4400 4780 5240
Planetary Density, Ê = 1 0.79 0.85 1.0 1.13 1.17 1.28
Escape Velocity, Ê = 1 0.60 0.76 1.0 1.16 1.28 1.5
Escape Velocity, km/sec 6.7 8.6 11.2 13.0 14.4 16.8
Mass of Atmosphere, Ê = 1 0.19 0.43 1.0 1.43 1.87 2.55
Mass of Atmosphere, Nx10^21 grams 1.0 2.4 5.3 7.6 9.9 13.5
Surface Pressure (lbs/²) 6.2 9.5 14.7 17.2 19.0 21.7
Rate of Rotation (hours) 23.2 20.2 17.0 15.3 14.4 12.8
Incoming energy absorbed by the Atmosphere., Ê = 1 0.79 0.85 1.0 1.13 1.17 1.28
General Planetary description. Small Dry Small Damp Medium Wet Medium Wet Large Liquid Large Aquatic

.

Incoming radiation
The next step in determining the factors which affect average planetary surface temperature was to create a graphic in which there was an alignment between APST and radiant  energy heating the planet’s surface at the equator; this criteria was further correlated with the planetary cloud cover. (From the Determining Incoming Radiation Diagram above).

After computing (with a slide rule) the surface values for Earth and Mars and positioning them in the chart’s grid at their known APST, percent cloud cover and mass, the graph then provided a scale from which to determine the equatorial surface radiation energy levels for our planetary models.

 Having derived the amount of radiant energy striking a planet’s surface at the equator, thereby deducing its APST, it was necessary to track the sunlight back up through the atmosphere, add-on the albedo losses and end up with the solar constant (amount of ‘sunlight’) at the top of the atmosphere.
Definitions:
•  Solar constant: The amount of sunlight per square centimeter at the top of the planet’s atmosphere above the equator; the solar constant for Earth is 1.97 gm cal/cm² min.
•  Albedo: The amount of sunlight reflected back into space from the clouds, snow, sand, etc. The    albedo is expressed as a fraction of the total sunlight falling on the top of the planet’s atmosphere; on Earth, the albedo has a value of 0.36.

These relationships may be expressed as follows:

Radiant energy heating the planets surface at the equator = Solar constant – (albedo x solar constant)
1.28 gm cal/ cm² minute Ê =  2gm cal/cm² minute – (0.36 x  2 gm cal/ cm² minute)

In order to determine a table for the range of albedos used in our planetary models, I graphed the Martian cloud cover and albedo against those of Venus. See Determining Incoming Radiation diagram above.  Note that Earth has about a 47% cloud cover, which on the diagram, yields a 0.34 albedo. Since atmospheric scientists  have determined Earth’s albedo is 0.36, I felt my albedo Determination graph was well within the acceptable range of error that could be associated with a study of this nature.

NOTE: You do not need to do the following calculations to work with the SRAPO templates. The data: Solar Constant, % Energy absorbed by the Planets Atmosphere, % Albedo loss, Rate of (planetary) rotation and Latent Heat of Vaporization of Water are presented in Chapter 3: Climatic Factors, Table: Data for computing precipitation and evaporation rates.

Determining Solar Constants
The next step resulted in the graph Determining Solar Constant. This is the tool to use when trying to determine the solar constant of a planetary model. See the following page. With it,  you can choose a planetary mass and APST then derive the resulting percentage cloud cover and the solar constant. If for example, you choose a 0.25 mass planet with a 30ºC APST, find the intersect within the body of the graph. Now, read horizontally across to the left Y axis scale for a 32% cloud cover and down to the lower X axis scale for a 1.80 gm cal/ cm² min solar constant.

Orbital Radius
At this point, we have the ability to begin with a set of basic planetary conditions , planetary mass and APST, and derive a specific solar constant.

The next question was, “How far is the planet from its parent star?” To answer this, you must first choose a Main Sequence star by its spectral classification,  thereby selecting its luminosity relative to the Sun. See Stellar Parameters, page 37.

With the following equation, you can calculate a habitable planets orbital radius about the given spectral class of star.

Radius of the planet’s orbit = The stars Luminosity (where Š =1) / the planets Solar Constant (where Ê = 1)
R2 =  L/S

At this point, we’ll stop and review the pieces of information we have deduced about our planetary models.

In the chart above: Cloud Cover is in the left axis. The amount of ‘sunlight’ hitting the top of the planet’s atmosphere is along the bottom axis. Each diagonal line inside the chart represents a planet of given mass (0.25 to 3.0 Earth masses) each is shown with a sliding scale of average planetary surface temperature – which correspond to the planet’s cloud cover and how much sunlight arrives from its parent star (Sun).  Example: A planet of 0.25 Earth masses (bottom diagonal brown line) with a 60ºC APST would have a Stellar Constant of about 2.35 cal/cm² min and about a 45% Cloud Cover.

Concepts Illustration: In the drawing above there is a parent star. Sunlight travels some distance (the orbital radius) to the planet and hits the upper atmosphere, this amount of energy is the planets Solar Constant. Some of the light is reflected back into space from the Cloud Cover, and some reflected from the snow, ice or sand on the surface, the average amount lost by reflection is the planet’s Albedo.

The drawing also shows an undefined land to water ratio and some percentage Cloud Cover. By choosing a planet’s mass and the APST, and plugging those values into the diagrams  found earlier in this chapter, you get the Solar Constant. This is important in determining how far the planet is away from its parent star, but more about that in a while.

Planetary Rate of Rotation
Based on observation of our own solar system, it appears that a planet’s rate of rotation is a function of its mass. The correlation between rate of rotation and mass is not perfect; however, the trend seems to indicate that it is not due to chance alone.

A reasonable theory that could explain the planet’s rotation is: During the process of planetary formation, by accretion, each particle of captured mass affects the rotational energy of the protoplanet. The net effect being an increase in the rate of rotation with an increase in mass.

Since all the planets in our solar system, except Uranus, rotate in the same direction as their orbital motion, its evident there is a tendency for incoming particles to impart a direct spin to the planet. Graphically, this may be seen as follows.

The mathematical formula expressing this relationship in hours per revolution (or more commonly ‘hours per day’)  is:

Hours / revolution = /(((2п/2MpK1)/K2R²)/3.6 x 10³ sec/ hr)

/ = square root
Mp = mass of the planet
R = the planet’s radius
K1 = constant, 1.46 x 10-19 cm² / sec² g
K2= constant, 0.4 (Maclauin’s spheroids)

The rate of rotation (length of day) imparted to a planet during its formation may be affected by tidal retardation. A relatively  large satellite orbiting the planet can slow the planet’s  rotation. This can be clearly seen in the Earth-Moon system. If Earth did not have the Moon in orbit, our ‘day’ would be seventeen hours, instead of twenty-four hours long.

Planets with an APST between 0ºC and 60ºC which are orbiting the relatively luminous stars of spectral class F through G, are at such a distance from their parent star that the rate of rotation is not affected. However, spectral class K stars are relatively cool stars and planets orbiting them must be in a very close orbit in order to fall with in the proper average planetary surface temperature range. Beginning with spectral class K2, the orbit for habitable temperatures is so close to the star that tidal retardation would arrest the planet’s rotation.

The habitable temperature zone around a star is called the ecosphere. We have set the ecosphere boundaries to provide the model planets an average planetary surface temperature (APST) range between 0ºC and 60ºC. The concept of ecosphere boundaries can be seen in the following diagrams.

Looking at the drawing above, we see that there are limits to the orbital diameter for a habitable planet. If the planet orbits inside the Inner boundary, the APST is above 60C and protein coagulates.; if it orbits beyond the Outer boundary, there is no liquid water.

If you will for a moment, turn back to the graph, “Determining Solar Constants’. Note that  for each planet there is given 0ºC to 60ºC temperature range. If you read from 0ºC on any planet to the Solar Constant scale on the bottom of the graph and again from 60ºC to the scale at the bottom, you will notice that these Solar Constants set the planet’s ecosphere boundaries, in terms of illumination arriving from the parent star.

By using the equation (discussed above):

L/ S = R²

Read the equation: The parent star’s Luminosity (where Š =1) [divided by] / the planet’s Solar Constant (where Ê = 1) [equals] = Radius of the planet’s orbit squared.

We can now locate a planet’s ecosphere boundaries in astronomical units.

1AU (astronomical unit) = 93 million miles

A planet whose rotation was being severely retarded might lose all of its surface water through photo-decomposition before the planet’s rotation was finally arrested. Once rotation was stopped, the planet might continue to orbit with one side always facing the parent star or it could enter a situation where one day equals a year.

Arrested planetary rotation
On planet which always present the same face to their Sun, the exposed side would be very hot and dry. If free water still existed on the planet it would have precipitated out of the atmosphere on the dark side and would exist as an ice pack. Wind circulation might follow the pattern: Cold, dry air flowing from the dark side would become hotter and hotter after it crossed the terminator (from darkness into light) to the exposed side of the planet. The vapor pressure deficit would cause rapid evaporation of any water brought to the surface by geysers, etc. As the winds move toward the center of the illuminated surface, they heat and rise higher and higher. This would in effect create a gigantic, permanent low pressure system on the illuminated side and a permanent high pressure system on the dark side.

One day equals a year 
On a planet with arrested rotation, where one day equals a year, the same type of atmospheric circulation would exist. Cool air would  cross the terminator near ground level, it would heat, rise and eventually flow back to the dark side. There is however, a major difference, the hot part of the planet and icepack would be in slow, but constant motion, around the planet as the year progressed. In this case, there would be an area associated with the moving terminator where water would exist in liquid form; however, it might do so for only a few weeks in any area.

The larger life forms we are attempting to resolve in this study, would probably not evolve on a planet whose rotation was arrested. It would be theoretically possible for such life to develop on a  arrested planet about a very cool star providing the parent star was part of a binary star system; SRAPO, however, does not directly address binary star systems.

We will then draw a general conclusion: Life as we know it will not exist on planets orbiting Main Sequence stars of spectral class K2 or lower, providing the star is isolated and not part of a binary or other complicated orbital star system.

Continued in Chapter 3: Climatic Factors

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