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Published online: 06 September 2004; | doi:10.1038/news040906-3 Waiting for ET

Philip Ball
Rumours of contact with aliens have been exaggerated (again). Philip Ball asks whether the search for extraterrestrials does anything but fuel paranoia.

SETI telescope collects data to enable research in the areas of astronomy, planetary studies, space and atmospheric sciences.

Those aliens... we just cannot figure them out. Just as we decide they are more likely to mail us than to radio us, they go ahead and beam us a message anyway. Maybe their copies of Nature aren't reaching them quickly enough.

On 2 September, Christopher Rose and Gregory Wright pointed out in Nature that, bit for bit, it is far more energy-efficient to send messages to other worlds as nanoscribed parcels than as encoded electromagnetic signals1. Yet that week also saw excited accounts in the press that claimed the SETI@home project had just reported its "most interesting signal" so far, coming from between Pisces and Aries at a frequency of 1420 megahertz. The project is the arm of the Search for Extraterrestrial Intelligence in which volunteers use their home computers to sift through radioastronomy data for signs of intelligent broadcasts.

Within hours of the first report, in New Scientist magazine, the news wires were humming. "Could space signal be alien contact?" asked Reuters. Britain's Daily Telegraph didn't mince its words: "Scientists tune in to 'radio message from the aliens'."

 It's all hype and noise 

Dan Werthimer
SETI chief scientist
But the SETI Institute scientists themselves are not jumping up and down about the signal, which they believe is most likely to be due to random noise. And they are not at all happy about the press attention. "It's all hype," says SETI chief scientist Dan Werthimer. "We have nothing that is unusual. It's all out of proportion."

Damping down

It is a familiar pattern: although scientists in many fields can only dream of attracting so much attention, SETI researchers spend their time struggling to bring everyone else back down to earth. But then, those involved in SETI probably have lower expectations of their studies than any other researchers on the planet. Failure is precisely what they anticipate. "We shouldn't have succeeded yet," cautioned astronomer and SETI senior scientist Frank Drake last month.

You could say Drake started the whole enterprise: he conducted the first ever radio search for alien intelligence back in 1960. His name is familiar from his famous equation for estimating the number of civilizations in our galaxy that are trying to communicate with us. To Drake, the equation was merely a formalized way of showing all the things we do not know. (It involves multiplying together a number of factors including the fraction of habitable planets on which intelligent life evolves, and the chances of those civilizations wanting to communicate with others.)

 We shouldn't have succeeded yet 

Frank Drake
SETI founder
He drew up the equation simply as a way of organizing the discussions about extraterrestrial intelligence that took place in 1960 at the radio observatory in Green Bank, West Virginia. This was a meeting of visionaries, including Carl Sagan, physicist Philip Morrison and biochemist Melvin Calvin. The previous year, in Nature, Morrison and his colleague Giuseppe Cocconi had proposed the idea of searching the skies for alien messages2, and Drake, with Sagan and others, went on to found the SETI Institute in 1984.

The Drake equation has become a touchstone of SETI efforts. But, as with so many things in this area, it has been interpreted far beyond its intended use. It is regularly quoted as if it were a formal proposal, and searching for aliens were a quantifiable science.

Fool's gold?

Debates about the value of SETI tend to be dominated by extremes: the cynics who deride it as a fool's quest, and the prophets who portray it as the most philosophically profound venture imaginable. What is clear is that SETI does not need anything in the way of results to capture the public imagination: Jill Tarter, the SETI scientist who provided the model for Jodie Foster's character in the movie Contact, was voted one of Time magazine's top 100 "people of power and influence" this year.

SETI's defenders point out that it costs nothing. The SETI Institute in Mountain View, California, is privately funded and the Allen Telescope Array currently under construction in California, which will carry out standard radioastronomy as well as SETI searches, is being supported by a US$13.5 million donation from Microsoft cofounder Paul G. Allen. And in terms of getting school children interested in science, searching for aliens beats even dinosaurs.

Of course, if Rose and Wright are correct, SETI may not be going the right way about its search. An alien civilization that wants simply to say "look over here" might indeed use electromagnetic signals. But if it wanted to tell us anything about itself, it would send out messages in bottles, or inscribed on giant black tablets in the hope that they would be discovered floating around Jupiter to the strains of Also Sprach Zarathustra.

But the project has a far more fundamental problem: it is trying, in good faith, to do science in an area where every false alarm is likely to become hot news, blown far out of proportion. When Britain's BBC runs a headline like "Astronomers deny ET signal report", as it did last Thursday, you can hear the conspiracy engines start running. Well they would say that, wouldn't they? They've probably been chatting with the Pisceans since Christmas.

Perks for the paranoid

Seth Shostak, SETI's senior astronomer, admits that the interest raised by false alarms is a problem. The poor man receives an unenviable stream of emails. "Check out the Pleiades," advises one correspondent, who has presumably figured out that would be a cosy part of the universe for aliens to live. Another reckons that the Sirius system is the best bet, because "the Dogon (a tribe in Mali) were visited by aliens who told them about the white dwarf star that orbits Sirius A". Other suggestions include tuning the receiving equipment to the wavelength of "brain transmissions" (but at what wavelengths do alien brains transmit?).

All this, like the furore over the latest 1420-megahertz signal, is scarcely SETI's fault. But it does raise the question: can a quest like SETI ever be conducted without fuelling the paranoid conviction, which has attained epidemic proportions in its host country, that the aliens have found us first?

  1. Rose C. & Wright G.Nature, 431. 47 - 49 (2004). | Article | PubMed | ISI | ChemPort |
  2. Cocconi G. & Morrison P. Nature, 184. 844 - 846 (1959). | ISI |

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