Could the same things that lead a theist think God is at the origin of life on earth lead an atheist to think Aliens are at the origin of life on earth ?
For example, if in 100 years it is shown that there are no initial conditions of the earth that could have lead life to originate, would this lead atheist to explore the idea that life could have been the product of aliens ?
Or would you really require evidence such as an actual documented encounter officially recognized as such with aliens to even entertain the idea in your mind that this could be a possibility ?