You are here

Searching for Neighbors

November 7, 2016

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

Get Premium Audio

Listen to today's episode of StarDate on the web the same day it airs in high-quality streaming audio without any extra ads or announcements. Choose a $8 one-month pass, or listen every day for a year for just $30.