re: Close up of Andromeda galaxy shows how many stars there really are

And even more to ponder is that a lot of the stars you see in the pic are actually part of a binary (or more) system. The estimate of the percentage of how many are in binary systems has fluctuated throughout the years but needless to say there’s a lot.

Planets have proven to be very common as well and my gut feeling tells me that most stars do have them in some form or fashion orbiting them. So take all of those galaxies which have all of those stars and now imagine all of those planets. Each system certainly doesn’t have a rocky planet (or moon of a planet) within the Goldilocks zone where water can be liquid, but given the sheer number of possibilities out there I think it’s all but impossible life hasn’t evolved elsewhere.