I was at an astrobiology conference this week, and one of the ideas that we discussed is that life on Earth is good at finding and exploiting gradients for ener

I was at an astrobiology conference this week, and one of the ideas that we discussed is that life on Earth is good at finding and exploiting gradients for energy harvesting---thermal, chemical, even electrical. I'm not sure how to weight the whole "the atmosphere will freeze out" argument, but it does seem like having a constant, predictable thermal gradient, coupled with lower average high energy radiation (not much UV at sunset), should be conducive to life, all else being equal.