There are two options if a person is lost in the wilderness. They can search for civilization, or they can make themselves easy to spot by building a fire or writing HELP in big letters. The options for scientists interested in the question of intelligent aliens are the same.
Astronomers have been looking for signals from other civilizations in the search for SETI for over 70 years. Most scientists believe that there is life on many of the 300 million planets in the universe. Some life forms may have developed intelligence and technology. The Great Silence is a mystery that has never been solved.
SETI has long been a part of mainstream science, but METI has been less common.
I am a professor of astronomy and have written extensively about the search for life in the universe. I serve on the advisory council for a nonprofit research organization that designs messages to send to extraterrestrial civilizations.
In the coming months, two teams of astronomy are going to send messages into space in an attempt to communicate with intelligent aliens.
These efforts are similar to building a big bonfire in the woods and hoping someone finds you. Some people are wondering if it is wise to do this.Advertisement
There were quixotic messages in a bottle when attempts were made to contact life off Earth.
The Pioneer 10 craft carried a plaque with a line drawing of a man and a woman and symbols to show where it came from. The Golden Record was attached to the Voyager 1 spacecraft.
The solar system has now all left the craft. The odds of physical objects being found in space are minuscule.
It's a much more effective beacon if it's radiation.
The first radio message designed for alien ears was beamed in 1974. The series of 1s and 0s was sent to the M13 to convey information about humanity and biology. You shouldn't hold your breath for a reply since M13 is 25,000 light-years away.
For nearly a century, stray signals from television and radio broadcasts have been leaking into space. Millions of stars have already been reached by this bubble of earthly babble. There is a big difference between a focused blast of radio waves from a giant telescope and a weak signal from a show like I Love Lucy.