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Searching for Neighbors
The recent announcement that our closest neighboring star has a planet set off a lot of speculation about life. Proxima Centauri b is a bit bigger than Earth. Most important, it lies inside the habitable zone — the distance from the star where temperatures are just right for liquid water. That means conditions could be comfortable for Earth-like life.
So far, though, we have no evidence of any life on Proxima Centauri b or anywhere else beyond Earth. But that hasn’t stopped astronomers from looking. In fact, they’ve been hunting for signals from other civilizations for more than half a century.
The hunt is known as SETI — the search for extraterrestrial intelligence. It mainly uses radio telescopes to listen for messages beamed into space by other civilizations, or for the high-powered signals of military radar or similar technology.
Most of the searches done so far have listened to a limited number of radio frequencies, or they’ve operated for a fairly short amount of time. But a new search will examine a wide range of frequencies for several years; more about that tomorrow.
Other SETI techniques are also coming online. Some are looking for high-powered lasers, for example. Others are looking for odd dips in a star’s light that might be caused by artificial structures passing in front of it.
These and other techniques may help us find if we have neighbors elsewhere in the galaxy — or if we travel through the vast Milky Way alone.
Script by Damond Benningfield