The Life of Super-Earths


Dimitar Sasselov, Central, 576.839 S2528L 2012

Interesting information about Super-Earth discovery and inferences about their geophysics, and some dated information about the emergence of life on Earth. Read Nick Lane's "The Vital Question" for an outstanding, cutting edge, but intellectually demanding description of life's emergence and development.

Clearly, geology played a crucial role, but it is questionable whether vastly more energetic geological processes on a higher gravity Super-Earth would produce robust life more easily, or merely wipe out life's fragile beginnings. I was hoping the author would at least touch on the pros and cons.

The regurgitation of the simplistic "habitable zone" description neglects the effect of vertical temperature lapse rate ( -5C per vertical kilometer on Earth, more if gravity is higher). The Earth's temperature is below freezing in the upper atmosphere where much of the heat is radiated as infrared. If our atmosphere was much thinner the surface would be frozen, and if it was much thicker the water would be vaporized, trapping more heat and baking the surface until the water dissociated and the hydrogen was lost (like Venus).

So; read the first half of this book to learn about the discovery of Super-Earths and their characterization. Read something else to learn about astrobiology.

LifeSuperEarths (last edited 2017-02-15 20:47:01 by KeithLofstrom)