It’s Easier for Aliens to Visit Us Than Previously Thought

A new study suggests that by using the slingshot effect to propel self-replicating probes through interstellar space, an advanced extraterrestrial civilization should be able to visit every corner of the galaxy in a startlingly short amount of time. The Fermi Paradox, it would seem, is alive and well. » 7/25/13 8:15am 7/25/13 8:15am

Why would aliens come all this way just to invade Earth?

In movies, when aliens invade our planet, they usually have a ludicrous motivation. Like, they're after our water. Or our gold. (Hint: Asteroids have gold.) Space travel is incredibly difficult and expensive — so why would aliens actually bother to come and invade us? We asked some experts for reasons that actually… » 5/02/13 1:30pm 5/02/13 1:30pm