Fears over new Seti plan to repeatedly broadcast greetings to habitable planets for hundreds of years dismissed as paranoia

Fears that a major program to contact alien life could spell disaster for planet Earth were dismissed as “paranoid” on Thursday by scientists who hope to beam messages to distant worlds from powerful radio telescopes.



Researchers at the Search for Extraterrestrial Intelligence (Seti) Institute in California want to broadcast greetings to potentially habitable planets in the hope of receiving a reply, but the proposal has met with serious objections from critics, including the cosmologist Stephen Hawking, who claim that yelling into space is reckless.



Astronomers have listened for signals from alien civilisations since 1960, when the Cornell University astronomer Frank Drake co-opted the national observatory at Green Bank, West Virginia, to launch Project Ozma. In more than 50 years since, no convincing signals have been picked up.



Faced with half a century of silence, Seti astronomers have decided it is the time to change tack. They propose to use radio telescopes, such as the Arecibo telescope in Puerto Rico, to beam repeated signals at nearby planets selected for their odds of harbouring life. They claim the approach is more promising than earlier attempts to gain alien attention, such as the plaques attached to Pioneer probes launched in 1972 and 1973 that depicted a naked couple waving hello.



Facebook Twitter Pinterest Fear of aliens have a grip on popular imagination, often heightened by sci-fi movies. Photograph: Allstar/20TH CENTURY FOX/Sportsphoto Ltd./Allstar

Radio signals bearing messages for aliens have been sent before. In 1974, the Arecibo telescope beamed an image of a stick man and the DNA double helix to a cluster of stars 21,000 light years away. In 1999, Russian scientists sent their own messages from Yevpatoria telescope in Crimea. In 2008, the US space agency, Nasa, beamed the Beatles song “Across the Universe” across the universe. Or at least at the North Star, 431 light years away.



Under an active Seti program, messages would be encoded in powerful radio signals and sent repeatedly for hundreds of years to planets that lie in the habitable zones around stars. Seth Shostak, director of the Seti Institute, advocates beaming the entire contents of the internet, giving an intelligent recipient the opportunity to decipher the history of human culture, the rules of cricket, and countless hours of porn.



“Even aside from the possibility that you might get information back from a very advanced society – like here’s all of physics or the cure for death – any response would tell you Earth is not a miracle, that it’s just another duck in a row,” said Shostak.

Active Seti, as the approach is called, is not universally supported though. Hawking has warned that Earth’s own history provides ample evidence that an encounter with more advanced ETs could go badly for humans. By drawing attention to ourselves, he notes, Earthlings might suffer the same fate as befell Native Americans when Columbus landed in America. Others agree. Simon Conway Morris, an evolutionary paleobiologist at Cambridge, has urged governments to prepare for the worst because aliens might be as violent and greedy as humans – or worse.

Facebook Twitter Pinterest Above, images and symbols etched on Nasa’s Pioneer plaque that was attached to the Pioneer 10 spacecraft before it was launched into space on 2 March 1972. Photograph: NASA/Getty Images

But the Seti scientists have now fought back. “It’s clearly too late to worry about provoking aliens with deliberate transmissions. Any alien society that is advanced enough to launch an attack and vaporise Swindon can easily pick up the broadcasts we’ve been sending into space since the second world war,” said Shostak,



He argues that a ban on sending signals into space would have to proscribe airport and military radar systems and even city lighting which can betray the existence of technology on Earth. “Such paranoid actions would cripple the activities of every succeeding generation of humanity,” he told the American Association for the Advancement of Science meeting in San Jose.

Douglas Vakoch, Seti’s director of interstellar message composition, argues that while it is prudent to assess the risks of alien contact, the extreme cases of annihilation or salvation are unrealistic. “Hawking said whatever you do, don’t transmit, they’ll come here and strip-mine the Earth. Now he’s a genius, but he can’t predict the future,” he said.



According to Vakoch, a civilisation only three hundred years ahead of ours could detect Earth’s TV signals at a distance of 500 light years. “We have already yelled ‘Yoo Hoo!’ We now want to follow up with something with a little more substance,” he said.



Facebook Twitter Pinterest Prof Stephen Hawking has described yelling into space as ‘reckless’. Photograph: Bruno Vincent/Getty Images

In 2009, Vakoch launched the Earth Speaks project which asked the public to submit messages to send to aliens. People from more than 70 countries responded. Some said hello. Many asked for help. Some women, and no men, offered coffee and cookies.

One of the greatest obstacles to making contact with ET is finding a common language. Vakoch considers maths a good bet, and advocates beaming formulations of game theory that demonstrate reciprocal altruism. “In other words, if someone does something good for me, I do something good back.”

Those opposed urge the scientists to pause. David Brin, a science fiction writer, questions why Shostak and others have to send bespoke signals into space if advanced civilisations already know we are here. “If they can already see us, why have they not responded?”

Brin calls for a temporary moratorium on sending messages into space until a global debate had approved the move. “I would leap in with both feet and make it a lovely online and TV extravaganza. Why the heck not? If they had a debate, they would attract so much more attention, so much more funding, and people would be better informed,” he said. “I don’t get why they have to be so secretive about it.”