How does the free energy on an ice moon compare to the amount the sun shoots down at earth?
Earth gets, on average, 340 watts per square meter of sunlight (more at the equator than the poles and more during the day than at night) for a total flux of 1.7 10^17 watts. Earth also has a geothermal heat flux (partially from primordial heat of formation, partially tidal heating, partially radioactive heating) of 4.7 10^13 watts for 0.087 watts per square meter (concentrated in hot spots of course). Our geothermal flux is thus about 1/4000 our solar flux. Only a fraction of the geothermal energy flux will be in a form available to living things, sp...
This is the first in a series of posts I am putting together on a personal blog I just started two days ago as a collection of my musings on astrobiology ("The Great A'Tuin" - sorry, I couldn't help it), and will be reposting here. Much has been written here about the Fermi paradox and the 'great filter'. It seems to me that going back to a somewhat more basic level of astronomy and astrobiology is extremely informative to these questions, and so this is what I will be doing. The bloggery is intended for a slightly more general audience than this site (hence much of the content of the introduction) but I think it will be of interest. Many of the points I will be making are ones I have touched on in previous comments here, but hope to explore in more detail.
This post references my first two posts - an introduction, and a discussion of our apparent position in space and time in the universe. The blog posts may be found at:
http://thegreatatuin.blogspot.com/2015/07/whats-all-this-about.html
http://thegreatatuin.blogspot.com/2015/07/space-and-time.htm