Hi, I don't know anything about astronomy so bear with me. How old is the solar system, and how old is that relative to the rest of the star systems in the galaxy? That is, is the solar system a young star system or an old one what? Is this just a function of the solar system's location in the Milky Way (i.e., older star systems toward the perimeter, younger towards the center, or vice-versa)? If it matters, I'm entertaining thoughts on ETs and I'm wondering a bit about likelihoods. I'm just going to post a few rambling thoughts here: 1) I take transhumanism as a given, and that it will make humans a potentially very dangerous species in this century (if you don't buy transhumanism that's okay, but let's not make this a TH thread); rapidly expansionist and extraordinarily dangerous to enemies. 2) I take it as a given that a logical, advanced, spacefaring race would give very serious thought to exterminating a species that showed strong signs of achieving direction 1) above. In fact, I think any biosphere could be argued to show that kind of potential and is a candidate for extermination. 3) Modern humans have been around for c. 100k years, and it wouldn't take a galactic genius to figure out their potential for 1). 4) The Milky Way is roughly 100k light years across (correct me if I'm wrong there, as I know nothing of astronomy) and the speed of light represents an absolute bounds on the speed of travel as far as we know (practical limits are likely to be significantly lower). Obviously I'm going somewhere with this (it isn't "there is no intelligent spacefaring species in the Milky Way" so don't worry), but I'd like to hear some thoughts since I don't know exactly where I'm going with this. :D Any SETI nerds here who want to help me throw this around? Edit: http://spaceflightnow.com/news/n0408/17milkyway/ I just found that and I haven't read through it, but this speculation is very interesting and germane.