SETI has no plans to actually send the messages into space. Vakoch said that before anything like that is undertaken, it should be subject to international discussion.
The first serious effort to contact intelligent life outside Earth was made in 1974, using the big radio telescope at Arecibo, Puerto Rico. The three-minute transmission by a group at Cornell University attempted to describe Earth and its inhabitants in binary code.
Over the last few years, a Russian group has sent greetings in Russian and English to targeted stars in our galactic neighborhood, generating a major dust-up in the small but passionate SETI community. Critics say the Russians are acting out of turn, without asking permission to open what would amount to diplomatic relations with another civilization. The problem is that nobody has the authority to grant permission.
Some observers say there is no need for us to broadcast a message. We're already doing that in the form of leakage into space of our radio and television signals. Those signals, however, are much too weak to travel far. A coordinated communications effort would require a powerful transmitter, a highly focused beam and a receiver pointed in the right direction.
Tarter acknowledged that there is plenty of reason to be cautious about replying to an alien signal.
"We're in an asymmetric position," she said. "We don't know if there are other civilizations out there, but if there are, we can be pretty sure we are the youngest." And, therefore, the most vulnerable.
Earthlings have had the technology to broadcast and receive electromagnetic waves for about a century. But the galaxy has been around for billions of years.
Any civilization that contacts us is likely to be much older.
"As the new kids on the block, we should listen first" and reply later, Tarter said.
--
john.johnson@latimes.com
