How would humanity change if we knew aliens existed?

We have yet to discover any signs of an extraterrestrial civilization — a prospect that could quite literally change overnight. Should that happen, our sense of ourselves and our place in the cosmos would forever be shaken. It could even change the course of human history. Or would it? » 2/14/14 8:10am 2/14/14 8:10am

Some of the Most Plausible Scenarios for Alien Civilizations

We have yet to make contact with an extraterrestrial intelligence, making it exceedingly difficult for us to imagine what an alien civilization might be like. But that doesn’t mean we can’t make some educated guesses. Here’s what we know — and don’t know — about aliens. » 11/04/13 11:00am 11/04/13 11:00am

How we could start looking for alien transmitters in our solar system

SETI now has the technology to go snooping for extraterrestrials in our own backyard. No, not as close as little green men cutting up crop circles. Rather, we should be able to detect an alien device positioned somewhere between the sun to 30 times farther out than Pluto. » 10/17/13 1:30pm 10/17/13 1:30pm

Meet SETI's new boss: Geoff Marcy, the planet hunter

Geoff Marcy has spent the better part of his career peering into the depths of space in the search for exoplanets and brown dwarfs. His pioneering work has resulted in the discovery of over 110 planets outside of our own solar system - including the first system of planets orbiting a distant star. But now, Marcy has… » 6/08/12 7:10am 6/08/12 7:10am