This article was originally published at Conversation. Publications that contributed articles to Space.com’s Expert Voices: Op-Ed & Insights.
Chris ImpeyDistinguished Professor of Astronomy, University of Arizona
If one gets lost in the wilderness, they have two options. They can look for civilization or they can easily spot themselves by lighting a fire or writing HELP in large letters. For scientists interested in the question of whether intelligent aliens exist, the options are the same.
For more than 70 years, astronomers have been detecting radio or optical signals from other civilizations in search of extraterrestrial intelligence, known as SETI. Most scientists believe that life exists on many of the 300 million habitable worlds in the Milky Way galaxy. Astronomers also suggest that it is very likely that some life form has developed intelligence and technology. But no signal from another civilization has been detected, a mystery known as the “Great Silence.”
Related: Why are we still searching for intelligent alien life?
While SETI has long been part of mainstream science, METI, or extraterrestrial intelligence, has been less popular.
I am a professor of astronomy who has written extensively about the search for life in the universe. I also serve on the advisory board for a nonprofit research organization that is designing messages for extraterrestrial civilizations.
In the coming months, two groups of astronomers will send messages into space in an attempt to contact any intelligent aliens that may be listening.
These efforts are like lighting a big bonfire in the woods and hoping someone finds you. But some question whether doing this is wise.
History of METI
Early attempts to contact extraterrestrial life were strange messages in a bottle.
In 1972, NASA launched the Pioneer 10 spacecraft towards Jupiter carrying a plaque with the lines of a man and a woman and symbols to indicate where the spacecraft came from. In 1977, NASA followed this up with the famous Gold Record mounted on the Voyager 1 spacecraft.
These spacecraft – as well as their twins, Pioneer 11 and Voyager 2 – have now left the solar system. But in the vastness of space, the odds that these or any other physical objects will be found are extremely small.
Electromagnetic radiation is a much more effective beacon.
Astronomers emitted the first radio message designed for alien ears from the Arecibo Observatory in Puerto Rico in 1974. Strings of 1s and 0s were designed to convey simple information. on humanity and biology and sent to globular cluster M13. Since M13 is 25,000 light-years away, you shouldn’t hold your breath to answer.
In addition to these purported attempts to send a message to aliens, silly signals from TV and radio programs have been leaking into space for nearly a century. This ever-expanding earth bubble has grown to millions of stars. But there’s a big difference between a focused burst of radio waves from a giant telescope and a diffuse leak – the weak signal from a show like “I Love Lucy” fades under the noise of the radiation. radiation left over from the Big Bang shortly after it left the solar system.
Send a new message
Nearly half a century after the Arecibo message, two international astronomical teams are planning new efforts at communicating with extraterrestrials. One is using a giant new radio telescope, and the other is choosing a fascinating new target.
One of these new messages will be delivered from the world’s largest radio telescope, in China, around 2023. The telescope, with a diameter of 500 meters (1,640 feet), will project a series of pulses radio in the vast sky. . These on-off pulses are like 1s and 0s of digital information.
The message is called “The Beacon in the Galaxy” and includes prime numbers and mathematical operators, the biochemistry of life, the human form, Earth’s position, and timestamps. The team is sending messages to a group of millions of stars near the center of the Milky Way, about 10,000 to 20,000 light-years from Earth. While this maximizes the potential pool of aliens, it could mean tens of thousands of years before Earth can get an answer.
The other attempt only targeted a single star, but was likely to respond much faster. On October 4, a team from the Goonhilly Satellite Earth Station in the UK will broadcast a message towards the star TRAPPIST-1. The star has seven planets, three of which are Earth-like worlds in the so-called “Goldilocks zone” – meaning they could also be home to liquid and potentially life. TRAPPIST-1 is only 39 light-years away, so it could take up to 78 years for intelligent life to receive its message and Earth to receive an answer.
The prospect of alien contact is ripe with ethical questions, and METI is no exception.
The first is: Who speaks for the Earth? In the absence of any international consultation with the public, decisions about what message to send and where to send it are in the hands of a small group of interested scientists.
But there is also a much deeper question. If you get lost in the woods, being found is obviously a good thing. When it comes to whether humanity should broadcast a message to aliens, the answer is far less clear.
Before his death, iconic physicist Stephen Hawking was candid about the dangers of coming into contact with aliens with superior technology. He argued that they could be the earth and that if given the position of the Earth, they could destroy humanity. Others see no added risk, since a truly advanced civilization would know of our existence. And profitable. Russian-Israeli billionaire Yuri Milner has offered $1 million for the best design of a new message and an effective way to deliver it.
To date, there are no international regulations governing METI, so trials will continue, despite concerns.
For now, intelligent aliens are still in the realm of science fiction. Books like “The Three-Body Problem” by Cixin Liu offer insightful and thought-provoking insights into what the success of METI efforts might look like. It doesn’t end well for humanity in the book. If humans come into contact in real life, I hope the aliens will come in peace.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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