So far, the search for extraterrestrial life beyond our solar system has focused on finding Earth-like planets. And sure, planets are great, since we know at least one of them harbors life. But David Kipping of the Harvard-Smithsonian Center for Astrophysics thinks that search might be a tad too narrow. In a new paper, Kipping described how current technology can be re-tasked to search for another life-bearing body: moons.
Looking for extraterrestrial life on moons is nothing new. After all, the search for alien life within our solar system generally focuses on Jupiter's ice moon Europa. However, this is the first time anyone has proposed looking for moons with life outside of our solar system.
The method suggested in the paper involves measuring changes in the orbit of large planets caused by the presence of moons. A similar technique, detecting the wobble of stars by the gravity of large planets, lead to the discovery of the first planets outside our solar system. This just refines that technique to smaller bodies. The paper identifies 25,000 stars close enough and visible enough to warrant further inspect, with a goal of finding a moon as small as 20 percent the size of Earth, and as large as our planet.
Of course, in the event that they find a habitable moon, we have to make sure it's not inhabited by annoying, ursine guerrillas, as they seem to be able to defeat an entire legion of the Emperor's best troops with nothing but sticks and rocks. Those are some aliens you don't want to mess with.