Finding an intelligent alien civilization would easily rank among the most profound discoveries in human history.
So far, though, there are no signs of communicating extraterrestrial life, no messages from the stars suggesting that humans are not alone in the universe. Maybe, some scientists argue, it’s time for us to take a more active role in the interstellar conversation. Instead of simply eavesdropping on the cosmos as we’ve done for the past half-century, perhaps Earth should begin transmitting messages to the stars – big, blazing telegrams meant to prompt an extraterrestrial reply.
But actively sending signals into the cosmos is more than a slightly controversial idea. Recently, a statement posted online asserted that messaging extraterrestrial intelligence (METI) carries “unknown and potentially enormous implications and consequences.” Signed by a number of well-known scientists – and people such as Elon Musk – the missive asks that a vigorous international debate take place before any new messages are sent.
That debate erupted at the American Association for the Advancement of Science’s annual meeting, where several contentious exchanges broke out as scientists gathered to discuss the pros and cons of interstellar messaging.
“We should launch active SETI as an ongoing complement to our traditional passive SETI projects,” said Doug Vakoch, director of interstellar message composition at the SETI Institute. “It’s a matter of diversifying our search strategies.”
But undertaking a targeted interstellar messaging campaign without considering the potential consequences is foolish, argued astrophysicist and science fiction author David Brin. The seeming lone voice of dissent among the convened panelists, Brin noted that attracting the attention of an unknown advanced civilization could bring potentially disastrous results. And, he said, it’s impossible to predict whether aliens are going to play nice or be real jerks.
“This is the only really important scientific field without any subject matter,” Brin said. “It’s an area in which opinion rules, and everyone has a very fierce opinion.”
Right now, there are no official messages waiting in Earth’s interstellar outbox. But Vakoch and others are floating the suggestion of using the Arecibo Observatory’s mega-powerful transmitter to send a series of messages in the down time between the observatory’s other studies. It wouldn’t cost much at all, and it would join the ongoing campaigns to listen for alien transmissions. While the question of what to include in those messages is obviously important, it’s taking a backseat to the issue of whether those messages should be sent at all.
“Active SETI, I gotta admit, is a controversial topic,” Vakoch remarked.
Despite the ongoing controversy, it wouldn’t be the first time interstellar messages have been beamed into space. A handful of transmissions have already left Earth’s shores and set sail across the cosmos. Perhaps the best known of these messages was sent from Arecibo in 1974, as part of a ceremony marking the completion of an upgrade to the giant radio telescope. Composed by astronomer Frank Drake, the message has been hurtling through space at the speed of light, destined to intersect in 25,000 years with a globular star cluster in the constellation Hercules.
And then there’s all the stuff that’s wafting into space without any such effort from Earthlings. These murmurs from Earth include the high frequency chirping of military radars, TV and radio transmissions, and the interplanetary radar used to study numerous asteroids in the solar system. Recently, technologies like cell phones and cable TV have turned Earth into a slightly quieter pale blue dot, but for many decades, our intra-planetary communications were easily leaking into space.
True, those signals are much harder to detect than a blast of directed radio waves from Arecibo, but SETI Institute senior astronomer Seth Shostak argued that any civilization advanced enough to show up and annihilate the planet is also advanced enough to detect those murmurs. In fact, he notes, our technology isn’t too far from being able to do the same. “We are within one or two centuries of being able to find the equivalent of ourselves,” he said.
In other words, it’s too late to shut up and hide.
But Brin isn’t buying it. And he bristles at the suggestion that he and his colleagues are simply worried about “slathering Cardassian invaders.” Instead, he implores, wouldn’t it make more sense to have a conversation about the potential ramifications of METI before we begin shouting into the void?
It does seem like a conversation is beginning to take place.
At the meeting, several panelists attempted to cut through the supposition and opinion by drawing analogies between METI and other controversies. Astrobiologist David Grinspoon noted the obvious link between METI and NASA’s Planetary Protection Office, created to prevent biological contaminants from being passed between Earth and other solar system bodies. “That’s a discussion that’s been had internationally, and I think that’s quite relevant here,” Grinspoon said. He also noted that fears of extraterrestrial intelligences with nefarious intent are not dissimilar to concerns about the motivations of artificial intelligence.
“That certainly presents an existential threat. It may be tiny — people have different opinions on it – but how are we dealing with that?” Grinspoon asked, noting that no one has shut down artificial intelligence research.
Later, federal judge David Tatel offered the rather salient observation that this debate is not unlike the controversy swirling around dual-use research on harmful pathogens, where learning more about nasty viruses could be used to engineer an especially potent bioweapon. And noted similarities with the current debate over geoengineering and how to combat climate change.
“Both of these have similarities with active SETI,” he said. “Both could produce great benefits or have catastrophic consequences.”