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.<\/p>\n\n\n\n
For over 70 years, astronomers have been scanning for radio or optical signals from other civilizations in the search for extraterrestrial intelligence, called SETI<\/a>. Most scientists are confident that life exists on many of the 300 million potentially habitable worlds<\/a> in the Milky Way galaxy. Astronomers also think there is a decent chance some life forms have developed intelligence and technology<\/a>. But no signals from another civilization have ever been detected, a mystery that is called \u201cThe Great Silence<\/a>.\u201d<\/p>\n\n\n\n While SETI has long been a part of mainstream science, METI<\/a>, or messaging extraterrestrial intelligence, has been less common.<\/p>\n\n\n\n I\u2019m a professor of astronomy<\/a> 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\u2019s designing messages to send to extraterrestrial civilizations<\/a>.<\/p>\n\n\n\n In the coming months, two teams of astronomers are going to send messages into space in an attempt to communicate with any intelligent aliens<\/a> who may be out there listening.<\/p>\n\n\n\n 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.<\/p>\n\n\n\n Early attempts to contact life off Earth were quixotic messages in a bottle.<\/p>\n\n\n\n In 1972, NASA launched the Pioneer 10 spacecraft toward Jupiter carrying a plaque with a line drawing of a man and a woman<\/a> and symbols to show where the craft originated. In 1977, NASA followed this up with the famous Golden Record<\/a> attached to the Voyager 1 spacecraft<\/a>.<\/p>\n\n\n\n These spacecraft \u2013 as well as their twins, Pioneer 11 and Voyager 2 \u2013 have now all left the solar system<\/a>. But in the immensity of space, the odds that these or any other physical objects will be found are fantastically minuscule.<\/p>\n\n\n\n Electromagnetic radiation is a much more effective beacon.<\/p>\n\n\n\n Astronomers beamed the first radio message designed for alien ears from the Arecibo Observatory<\/a> in Puerto Rico in 1974. The series of 1s and 0s<\/a> was designed to convey simple information about humanity and biology and was sent toward the globular cluster M13. Since M13 is 25,000 light-years away, you shouldn\u2019t hold your breath for a reply.<\/p>\n\n\n\n In addition to these purposeful attempts at sending a message to aliens, wayward signals from television and radio broadcasts have been leaking into space for nearly a century. This ever-expanding bubble of earthly babble has already reached millions of stars. But there is a big difference between a focused blast of radio waves from a giant telescope and diffuse leakage \u2013 the weak signal from a show like \u201cI Love Lucy\u201d<\/a> fades below the hum of radiation left over from the Big Bang soon after it leaves the solar system.<\/p>\n\n\n\n Nearly half a century after the Arecibo message, two international teams of astronomers are planning new attempts at alien communication. One is using a giant new radio telescope, and the other is choosing a compelling new target.<\/p>\n\n\n\n One of these new messages will be sent from the world\u2019s largest radio telescope<\/a>, in China, sometime in 2023. The telescope, with a 1,640-foot (500-meter) diameter, will beam a series of radio pulses over a broad swath of sky. These on-off pulses are like the 1s and 0s of digital information.<\/p>\n\n\n\n The message is called \u201cThe Beacon in the Galaxy<\/a>\u201d and includes prime numbers and mathematical operators, the biochemistry of life, human forms, the Earth\u2019s location and a time stamp. The team is sending the message toward a group of millions of stars near the center of the Milky Way galaxy, about 10,000 to 20,000 light-years from Earth. While this maximizes the pool of potential aliens, it means it will be tens of thousands of years before Earth may get a reply.<\/p>\n\n\n\n The other attempt is targeting only a single star, but with the potential for a much quicker reply. On Oct. 4, 2022, a team from the Goonhilly Satellite Earth Station in England will beam a message toward the star TRAPPIST-1<\/a>. This star has seven planets, three of which are Earth-like worlds in the so-called \u201cGoldilocks zone<\/a>\u201d \u2013 meaning they could be home to liquid and potentially life, too. TRAPPIST-1 is just 39 light-years away, so it could take as few as 78 years for intelligent life to receive the message and Earth to get the reply.<\/p>\n\n\n\n The prospect of alien contact is ripe with ethical questions, and METI is no exception.<\/p>\n\n\n\n The first is: Who speaks for Earth<\/a>? 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<\/a>.<\/p>\n\n\n\n But there is also a much deeper question. If you are lost in the woods, getting found is obviously a good thing. When it comes to whether humanity should be broadcasting a message to aliens, the answer is much less clear-cut.<\/p>\n\n\n\n [Understand new developments in science, health and technology, each week.<\/em> Subscribe to The Conversation\u2019s science newsletter<\/a>.]<\/p>\n\n\n\n Before he died, iconic physicist Stephen Hawking was outspoken about the danger<\/a> of contacting aliens with superior technology. He argued that they could be malign and if given Earth\u2019s location, might destroy humanity. Others see no extra risk<\/a>, since a truly advanced civilization would already know of our existence. And there is interest. Russian-Israeli billionaire Yuri Milner has offered $1 million<\/a> for the best design of a new message and an effective way to transmit it.<\/p>\n\n\n\n To date, no international regulations govern METI, so the experiments will continue, despite concerns.<\/p>\n\n\n\n For now, intelligent aliens remain in the realm of science fiction. Books like \u201cThe Three-Body Problem<\/a>\u201d by Cixin Liu offer somber and thought-provoking perspectives on what the success of METI efforts might look like. It doesn\u2019t end well for humanity in the books. If humans ever do make contact in real life, I hope the aliens come in peace.<\/p>\n\n\n\n Chris Impey<\/a>, University Distinguished Professor of Astronomy, University of Arizona<\/a><\/em><\/p>\n\n\n\n This article is republished from The Conversation<\/a> under a Creative Commons license. Read the original article<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":" Chris Impey, University of Arizona 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 […]<\/p>\n","protected":false},"author":44,"featured_media":29415,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[3410],"tags":[6685,218,145,11737,11738,6684,187,3417],"_links":{"self":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/29414"}],"collection":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/users\/44"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/comments?post=29414"}],"version-history":[{"count":2,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/29414\/revisions"}],"predecessor-version":[{"id":29422,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/29414\/revisions\/29422"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/media\/29415"}],"wp:attachment":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/media?parent=29414"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/categories?post=29414"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/tags?post=29414"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"A](\"https:\/\/images.theconversation.com\/files\/460140\/original\/file-20220427-24-lnf43y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip\")
<\/a>The history of METI<\/h2>\n\n\n\n
![\"A](\"https:\/\/images.theconversation.com\/files\/460135\/original\/file-20220427-17-yuvu1q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip\")
<\/a>Sending new messages<\/h2>\n\n\n\n
![\"An](\"https:\/\/images.theconversation.com\/files\/460136\/original\/file-20220427-16-5v9rcq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip\")
<\/a>Ethical questions<\/h2>\n\n\n\n