If a person is lost in the wilderness, they have two options. They can search for civilization, or they could make themselves easy to spot by building a fire or writing HELP in big letters. For scientists interested in the question of whether intelligent aliens exist, the options are much the same.
For over 70 years, astronomers have been scanning for radio or optical signals from other civilizations in the search for extraterrestrial intelligence, called SETI. Most scientists are confident that life exists on many of the 300 million potentially habitable worlds in the Milky Way galaxy. Astronomers also think there is a decent chance some life forms have developed intelligence and technology. But no signals from another civilization have ever been detected, a mystery that is called “The Great Silence.”
While SETI has long been a part of mainstream science, METI, or messaging extraterrestrial intelligence, has been less common.
I’m a professor of astronomy who has written extensively about the search for life in the universe. I also serve on the advisory council for a nonprofit research organization that’s designing messages to send to extraterrestrial civilizations.
In the coming months, two teams of astronomers are going to send messages into space in an attempt to communicate with any intelligent aliens who may be out there listening.
These efforts are like building a big bonfire in the woods and hoping someone finds you. But some people question whether it is wise to do this at all.
They already know our location. To read more, click here.