December 29, 2011, 11:51 AM — Scientists at Arizona State University are urging managers at projects such as the Search for Extraterrestrial Intelligence (SETI) to look for evidence of alien civilizations close to home in addition to scanning cosmic radiation in hopes of finding patterns that could be alien radio signals.
If there are advanced alien civilizations in the galactic neighborhood, they may well have done more than just tried so send us radio signals, according to a paper published by Paul Davies and Robert Wagner in the journal Acta Astronautica.
If there are intelligent alien civilizations in our neighborhood of the galaxy, they may very well have visited Earth to observe a developing intelligence, or steal the idea for Facebook and take it back home to violate the privacy of alien species as well as domestic ones, according to the (liberally paraphrased) reasoning in the article
If aliens had stopped by, they would need a base of operations, preferably one that was undetectable by human technology at the time, but offered resources such as water, gravity and, apparently, lots and lots of dust.
Most science-fiction stories and alien invasion conspiracies posit a mother ship in orbit several hundred miles above the earth, rather than 238,857 miles away on the moon. Orbiting bases would allow shuttle craft to visit earth, kidnap and probe occupants, then return them to their native trailer-park habitats without having to travel the whole distance to the moon.
However, even for advanced civilizations, the distance between star systems is so huge that any ship arriving here would presumably need to replenish their food, water and fuel or (if Hollywood B movies of the '50s are any indication) be desperately in need of physically incompatible women in beehive hairdos who scream a lot.
Davies, by the way, is no crackpot; or at least he's not one without academic credentials. He's a theoretical physicist and cosmologist studying astrobiology – the origin and evolution of life – and founder of ASU's Beyond Center for Fundamental Concepts in Science. (He's also giving a public lecture called "Time Travel: Can it really be done" at 7 PM Jan. 31 on the ASU Tempe campus – a lecture promoted using a poster with Dr. Who's TARDIS. That indicates, if nothing else, that he knows what science topics the public wants to hear about and in what obsolete police telephone-booth form it currently understands them.)