Before Ed Turner and Avi Loeb tell you about their research, they want to make one thing perfectly clear: they do not claim that there's a city on Pluto. But if there were one, they say, we could see it. And as they suggest in a paper they've submitted to the journal Astrobiology, it's worth taking a look, just in case. The whole thing began a couple of years ago, when Loeb and Turner, astrophysicists at Harvard and Princeton, respectively, were at a conference in Abu Dhabi. The organizers sent them on a tour of nearby Dubai, where the guide bragged that his gleaming, ultramodern city was so brightly lit at night that from space it would outshine London, Paris or New York City. (See pictures of deep space from the Hubble telescope.) That got the pair thinking: how far away could you see a major city on another world using existing telescopes? The question percolated for a while, until Loeb mentioned it to Freeman Dyson, the Institute for Advanced Study physicist famous for spending more time thinking outside the box than in it. (In the early 1960s, Dyson worked on the idea of a rocket propelled by atom bombs, and has suggested that astronomers look for aliens who might have enclosed their stars to trap solar energy.) Dyson was, predictably, intrigued by the question of extraterrestrial cities. "He encouraged us to write it up," says Loeb.
Almost hard to believe that they haven't bothered looking. To read more, click here.