Avi Loeb of the Harvard-Smithsonian Center for Astrophysics and Edwin Turner of Princeton University say they're going on the assumption aliens would use Earth-like technologies and that any intelligent life that evolved in the light from its nearest star is likely to have artificial illumination that switches on during the hours of darkness, a Harvard-Smithsonian release said Thursday.
"Looking for alien cities would be a long shot, but wouldn't require extra resources," Loeb said. "And if we succeed, it would change our perception of our place in the universe."
Distinguishing city lights on a planet from the glare of a parent star would be difficult, they acknowledge, and could require future generations of more sensitive telescopes.
As Earthly technology has advanced from radio and TV broadcasts to cable and fiber optics, we have become less detectable to aliens, and if the same is true of extraterrestrial civilizations then artificial lights might be the best way to spot them from afar, Loeb and Tuner say.