Discovering Planets Is Fun But We Are Really On A Quest To Find ET

Thursday, March 5, 2015

Discovering Planets Is Fun But We Are Really On A Quest To Find ET

Are We Searching For New Planets Or Intelligent Life

ONE of the sessions of the AAAS meeting was dedicated to planets in other solar systems, a field of enquiry which has blossomed as thousands of them have been detected. Finding such exoplanets is interesting in its own right, of course. But you do not have to scratch far beneath the surface to realise that the planets themselves are not the real motive. William Borucki, an astronomer who pushed for the construction of Kepler, the orbiting telescope responsible for locating most of the exoplanets that have so far been found, puts it plainly. He says that the whole enterprise is about discovering whether human beings are alone in the universe.

At the same time, just next door to the exoplanet seminar, a less well-attended session considered the matter from a markedly different angle—namely whether mankind should be sending signals into space in the hope that they might be detected by aliens. There has been a hotchpotch of efforts to do this already, ranging from one in 1974 by Frank Drake, a pioneer of the search for extraterrestrial intelligence (SETI), to an advertisement for Doritos, a snack food, that was beamed in the direction of a star in the constellation of Ursa Major in 2008. What is now being suggested, by Seth Shostak of the SETI Institute, in California, which leads the search for aliens, is a more concerted effort. He wants to use the world’s largest radio-telescope dish, at Arecibo in Puerto Rico, as a transmitter to beam some kind of radio greeting towards nearby stars.

There is vehement opposition to this plan, not least because it might pose a danger from the sort of malevolent aliens often depicted in science-fiction films. This has preoccupied no less a mind than that of Stephen Hawking, a theoretical physicist, who warned against the idea of seeking out contact in 2010. He remarked, by way of historical analogy, that past “first-contact” incidents between groups of humans, such as European explorers and native Americans, were not usually noted for their peaceability.

What has changed, as far as Dr Shostak is concerned, is a growing sense that first contact is inevitable. Humans have been spraying radio waves into the cosmos for quite a bit longer than anyone on Earth has been listening for signals coming the other way. The first television advertisements will already have passed about 200 sun-like stars. Better, he argues, to try to control the message by speaking deliberately to anyone who is out there than let them to form their own conclusions from ads for tortilla chips.

David Brin, an astrophysicist and science-fiction author, took to the stage to posit, ominously, that if aliens really are out there and Earthlings have not yet heard from them, perhaps those aliens know something that humans do not. Shortly before the meeting, Dr Brin and 27 others—including Geoff Marcy, an astronomer at the University of California, Berkeley, who is the single most prolific discoverer of exoplanets—penned a statement in opposition to the SETI Institute’s plan. “As a newly emerging technological species,” it reads, “it is prudent to listen before we shout.”

Both listening and shouting involve, of course, an extraordinary long-odds bet. All of the radio spectrum and much of the optical one might carry a message, or be used to broadcast one: the chances of alien interlocutors being on the right frequencies are low. And there is no guarantee that Earth’s present technological age of radios and lasers will align with the methods of a far-flung astronomer.

Should the bet come off, though, much is at stake. Dr Brin and other dissenters are not against broadcasting altogether, but argue that the decision of when and what to send ought to be the subject of a grand, global survey.

It might all sound rather esoteric, for it is unlikely an alien civilisation does exist—at least within the range of any sort of broadcast that is currently possible. But if someone does take it into his head to send messages out on the off-chance, then he will, by default, be speaking for the planet as a whole. And if there is a reply, the planet might just wish it had paid more attention to the matter.

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