With so many nice planets out there, why would aliens attack Earth?
The saga of extraterrestrials menacing Earth goes at least as far back as "War of the Worlds" — as in the 1898 H.G. Wells novel, not the 2005 Tom Cruise flick. But there's one question about that perennial plotline that bugs the SETI Institute's senior astronomer, Seth Shostak: Now that we'relearning that planetary real estate is so abundant in the Milky Way, why would the aliens bother attacking?
The real-life search for worlds beyond our solar system is eroding the motivation for a space alien menace, Shostak says.
NASA's Kepler planet-hunting mission suggests that there could be billions upon billions of alien Earths and super-Earths out there. "What is it we have to offer, aside from some pretty good fish up in Seattle?" Shostak asked NBC News. "The answer is, not much. Just our culture, really. That's the only thing that they won't have at home, where the shipping charges are less."