I'm not trying to start a new thread here - this is just for general reference on what I've called HAT (Hopeful Alien Theory). It's much older than I thought, like evolution it goes back to the ancient Greeks. It's called
panspermia
and I don't really want to continue the debate on it. I first came across it when researching the application of probability to evolution, and especially abiogenesis. The book by Coppedge was my starting point, but after pursing the idea for awhile I came across panspermia and realized atheists have an out even if evolution on earth were shown to be statistically impossible. So I quit pursuing the probability question.
Again, this is just for information since in came up in another thread - this article is a good summary for anyone interested.