Centauri Dreams admits to troubling new doubts about a variant of SETI called METI — Messaging to Extraterrestrial Intelligence. The notion, also known as ‘active SETI,’ is backed by some members of the SETI community and is especially strong in Russia. Its premise is that rather than listening passively for signs of extraterrestrials, we should actively try to achieve contact through messages of our own. This would constitute a ‘brightening’ of our civilization in the radio sky, making us more noticeable by many orders of magnitude.

A number of intentional signals besides the famous Arecibo message of 1974 have already been sent. The so-called ‘Cosmic Call 1’ message was transmitted from the Evpatoria Planetary Radar site in the Crimea in 1999, targeting four Sun-like stars and sending an overview of terrestrial life written in a code called Lexicon. Cosmic Call 2, sent to five Sun-like stars, followed in 2003. Based on the target list and the distances involved, the window for a possible response to these messages opens in sixty years.

Is this a good idea? We are only beginning to have some understanding of how many planetary systems are out there and to learn about the properties of their largest planets. Knowing what we know now about the tenacity of life on Earth even in the most extreme environments, and knowing that there may well be Earth-like worlds in solar systems throughout the galaxy, we face the real possibility of alerting other civilizations to our presence before we know anything whatsoever about them. This may or may not prove dangerous, but it seems like something that deserves wide discussion.

But the conversations now going on in the SETI community focus on the work of a small committee of the International Academy of Astronautics (IAA), one chaired by the SETI Institute’s Seth Shostak. You may know of this committee from its earlier work, as it developed the so-called ‘First SETI Protocol’ that outlines a rational response to the detection of an extraterrestrial intelligence. Such protocols are highly productive, for they bring the scientific community together before such a paradigm-changing event can occur, allowing for a thoughtful look at the issues and encouraging debate.

But there is a second protocol under discussion, one that asks METI proponents to hold back from deliberate transmissions until their plans can be examined in open gatherings by a broad community of experts in various disciplines. What is now under debate is whether such restraint is sensible or simply represents a paranoid response to a non-existent threat. The IAA meeting this October in Valencia may well ratify a protocol that accepts METI transmissions without requiring any further discussions to occur.

It is striking to me that there is only one science fiction author — astrophysicist David Brin — on the IAA committee that will decide these things. I would argue that writers like Brin, Gregory Benford, Greg Bear and others have spent years pondering the possibilities of interstellar contact and its ramifications. Their contribution would broaden this debate, which seems from my perspective to be focused on a tightly defined group of SETI proponents whose work could nonetheless have serious repercussions for the human future.

It would be useful to find out what readers think about this issue. Some have argued that it is already too late, that the broadening sphere of our radio and television transmissions is already well past numerous star systems and in any case cannot be called back. But such signals are far less visible than the beacon-like effects contemplated by some proponents of active SETI. METI proposes a genuine change in tactics, one that seems to cry out for sustained and highly visible debate before we raise Earth’s visibility.

Your thoughts?