One of the strengths of the community involved in the search for extraterrestrial intelligence—known as SETI—is its imaginative ability to take seriously things that most people dismiss out of hand.
The idea that the technologies of astronomy can go beyond allowing us new insights into the natural world, and provide us with a means of communication with alien beings, is not entirely hypothetical.
Artificial phenomena, such as civilizations, will certainly dissipate energy like natural energy – and may do so with the intent of communication. We on Earth send a mish-mash of unnatural-looking radio waves into the universe, not to mention a handful of neutrino beams.
But what if we add some deliberate hints to that mish-mash? If sufficiently beamed with the help of radio-telescope antennas, even a low-power radio transmission can stand out from a normal murmur to a star where it is aimed.
That’s the idea behind the so-called ‘active SETI’, which some enthusiasts think is a path to the field. There are others who think this is a small but real danger, and therefore needs to be discussed more broadly. But at the recent meeting of the International Academy of Astronautics SETI study group in Valencia, Spain, the mood of the gathering was with enthusiasts.
It’s easy to see the appeal of active SETI—it’s right there in the adjective. Traditional SETI involves looking at large amounts of radio data and searching for nothing. Active SETI allows you to compose messages, choose target stars, develop new encodings, and more.
It can be used as an outreach tool – the European television channel Arte is currently encouraging people to send it messages specifically to stars, to detect planets around distant stars The design is to the stars as part of the celebrations surrounding the launch of Corot, a French satellite. .
At the same time, however, the risk posed by active SETI is real. It is not clear whether all extraterrestrial civilizations would be benign – or that even contact with a benign person would not have serious implications for people on Earth. There is already an agreement within the SETI community that, if a further signal should be received, the various bodies will discuss what response, if any, should be sent.
Yet the Valencia meeting voted against any attempt to establish any procedure to discuss the style or content of any spontaneous outgoing messages. In fact, anyone who has a dish large enough can appoint himself as Earth’s ambassador.
The possibility of an active SETI producing unpleasant results with today’s technology is remote indeed, as it would require us to elevate ourselves to the threshold of detection for an alien civilization that happened to orbit that star. At which point the message was aimed, or to reveal some peculiar flaw in our psychological fabrication that alien ‘black-ops’ experts may begin working on ways to exploit. Either way, the damage, even if done at the speed of light, will take decades to come.
Yet these small risks should be taken seriously. When technologies offer radically new possibilities, even those who are privileged to play with them have a duty to consult extensively on what those possibilities might mean.
The SETI community should assess them in a discussion that is open and transparent enough for outsiders to listen and, if so, to participate actively. Of course, consensus may not always be possible – but the kind of debate that has a chance to emerge from consensus, it should be now.