It's a thankless task, but to Backus it's one well worth the effort. The monitors show the Arecibo Observatory, the largest one-dish radio telescope on earth. The day they show a clear and meaningful signal from another world could be the day Backus and his colleagues earn their place in the history of the cosmos.
"You can't really say, `This is going to be the day, and I'm going to quit if I don't get anything,' because the scope of our search is just so large and difficult," says the 44-year-old astronomer from the SETI (Search for Extraterrestrial Intelligence) Institute in Mountain View, California. "I would be shocked if we were alone."
It's been 15 years on and off without a significant peep, but Backus takes the situation in stride. "There's no place like Arecibo," he says.
It doesn't help that SETI is only allotted six weeks a year at Arecibo, a unique facility carved into the limestone hills and sinkholes 10 miles from Puerto Rico's northern Atlantic coast. Twice a year, for three weeks at a time, several members of the SETI team stay here to monitor the cosmos from 6 p.m. to 6 a.m.
The observatory was built in 1963 by the Department of Defense to study the outer part of the earth's atmosphere. It was placed near the equator to provide scientists with a better view of planets and stars passing overhead.
The receiver resembles a huge metal bowl dropped into a sinkhole, and allows researchers to listen to sounds in space instead of depending on optics, like the orbiting Hubble Space Telescope.
By capturing radio signals emitted by everything from stars to basic elements like hydrogen, astronomers have mapped galaxies, detected gas clouds, and come up with some of the first evidence of planets outside our solar system.
Such projects have been around for almost 40 years but with no success to date. In 1992, Congress approved a $100 million, 10-year search for extraterrestrial life. But the next year, congressional opponents of the program in got it cut from the NASA budget. SETI was rescued by donors, including Microsoft cofounder Paul Allen, who provided much of the institute's estimated $4 million annual budget.
So, is SETI ready for the day when the long-awaited signal comes?
Backus' colleague Seth Shostak says astronomers around the world have an informal agreement that if it comes, no one will send a reply until there is a worldwide consensus on what to say. "It would take forever," he jokes.
Then reconsidering the possibilities he says, "I'm sure everyone with a backyard satellite dish and the ability to build a transmitter will begin broadcasting their persona philosophies into space pretty quickly."
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