[“SRAPO is the eighth Journal of Larry Francis Pierce, being written in the year of our Lord 1985, at the forest homestead – Nightstar *”.
I began the SRAPO project during 1965, while in my first years of college. Twenty years later, in 1985, the study was reworked and entered into Journal #8, along with the associated charts, tables and my hand drawn illustrations. By the mid 1990s, SRAPO was converted into digital form; it is now being converted into the WordPress blog format.]
[Drawing, composite ‘Gray’] .
[Drawing, Eye-environments: In the paper version of this study, the page above showing the ‘alien’ head, has a circular hole cut out where the eye is seen. The eye coloration comes from the next sheet of paper (the drawing immediately above)– the centrally located blue planet, becomes the eye of the alien on the preceding page.]
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It is the purpose of this study to explore some plausible variations in extraterrestrial planetary ecology, particularly that of intelligent life forms.
Our primary environmental building block will include carbon based life utilizing liquid water as a solvent for chemical reactions. These and other limiting factors will be discussed as they’re approached in the text.
Data regarding Earth and the other planets in our solar system have been interlinked providing a basis for this study. In some instances, I’ve extrapolated, in that it was necessary to go beyond the given information to find a set of variations. Elsewhere, the absence of data has caused me to reason out a plausible scheme for variations, amongst environmental elements.
Periodically, you’ll see where I’ve entered the Earth standard or average to intuitively demonstrate the parameter being discussed.
By the time you’ve reached the end of this study: 1) you should have a basic understanding of exobiology and general planetology, 2) you will have a new appreciation of our home planet; 3) you’ll be able to write-up a SRAPO template for a hypothetical model world environment, one that might exist around a potentially habitable star system and, 4) if you hypothesize what an alien ‘looks’ like, you can plug the given characteristics into the SRAPO template and work backwards to find the type planet and a range of stars which it may have come from.
Keep in mind, Man could probably live, with varying degrees of difficulty, in at least one region on most of the planets covered in this study. Likewise, life in general and intelligent life in particular from these planetary models could survive, perhaps even thrive, in some of the environments found on Earth.
Table: Symbols and Terms
| APST | Average Planetary Surface Temperature. |
| Ê | The symbol for Earth |
| Ê= 1 | States that the parameter mentioned is being compared to the same condition on Earth, where the value on Earth is taken relatively, as 1.0. |
| Š | The symbol for our star, the Sun. |
| Š=1 | States that the parameter mentioned is being compared to the same condition on the Sun, where the value on the Sun is taken relatively, as 1.0. |
| small, weak | Relative terms which state that the given parameter is considered to have a smaller value than found on Earth. |
| moderate, average | States the parameter has a somewhat similar value as found for Earth. |
| large, great | Means the parameter has a greater value than found on Earth. |
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The ‘Various Limiting Factors illustration below, sets the basic ground rules, defining the most common conditions under which we might expect to find intelligent life.
4dtraveler 
Mr. Larry,
I recall your back bedroom, in Pasadena, El Molino St., where we tried to raise Molly and related fish. We spent hours discussing this subject. Lots of black board (hung on your wall) illustrations and calculations, etc.
As I recall, out of frustration, we finally decided we both needed much more ‘higher math” skills to continue… so we stopped.
Congrats on taking this so much further.