Waiting for Contact With Alien Life

April 23 -- Astrophysicist Jill Tarter is planning for the day alien life contacts Earth.

She's the director of the nonprofit, privately funded SETI Institute, which stands for the Search for Extraterrestrial Intelligence. For 16 years, the institute has conducted research and educational projects relevant to quest for life elsewhere in the universe.

Tarter has some ideas of what communication with extraterrestrial life might be like.

Lopsided Contact

"The contact between us and another intelligent species is inevitably going to be lopsided," she says. "We are a very young technology in a very old universe… An older technology will have had this contact before."

With powerful radio telescopes, SETI searches for signals from 1,000 stars.

"Our galaxy has 400 billion stars, so we're just looking on our back doorstep, our nearest neighbors," Tarter explains. Those 1,000 stars are like our own sun, Tarter says, and have been around long enough for evolution if time scales on Earth are typical.

Around those stars, scientists at SETI hope to find planets like our own, with habitable environments that could give rise to intelligent life.

And just how would planet Earth converse with an advanced civilization?

"I don't think we're going to understand immediately what they have to say," says Doug Vakoch, SETI's resident psychologist.

Communication would likely be very difficult. Any contact with advanced civilization will take place across vast amounts of space and time.

"It may not hurt to hold off, think about it for a few months, or a few years or even decades," Vacoch says.

If and when that time comes, Tarter says we'll have to think about who should represent Earth.

"Right now, we don't have any way of answering the question, 'Should we reply,'" she says.

Technically, who could speak for the planet?

"Anybody could, with enough transmitter power," Tarter says. "And I think, the best reason to say, 'let's talk about it in advance,' is to diffuse the idea that it will be hidden." Or that one nation would attempt to benefit by keeping the information secret.