By RYAN SABALOW
Scripps Howard News Service
June 04, 2007
For the last year or so, scientists at the SETI (Search for Extraterrestrial Intelligence) Institute's Hat Creek Radio Observatory, 75 miles east of Redding, Calif. have been installing and fine-tuning a set of 42 radio astronomy dishes.
The scientists have been working frantically to get the dishes ready for the day when they can all work together to listen for an alien radio signal.
That day could come as early as July, when scientists from the University of California at Berkeley are expected to install a device called a "beam former."
The device will effectively turn all 42 dishes into one big dish, making rural Shasta County the site of the world's largest space-scanning radio observatory, said Rick Forster, resident astronomer at the Hat Creek observatory's Allen Telescope Array.
"I don't think there's been a moment in history where people haven't looked up into the night sky and seen how truly massive it is and not wondered if we're the only sentient beings in the universe," Forster said.
Forster has a welcome mat outside his office that invites everyone -- even space aliens -- inside.
Like a radio operator turning the dial for that perfect signal, the dishes will be listening for ET around the clock -- the first time the Mountain View-based SETI Institute has had such a luxury, said Scott Hubbard, who holds the institute's Carl Sagan Chair for the Study of Life in the Universe.
"There are a number of groups around the world doing SETI research," Hubbard told Reuters last week. "They are listening for radio signals out there, but it is not 24/7."
Outside the window of Forster's office, the sun glinted off the 42, 20-foot-tall dishes, which sit at the bottom of a lava-rock encrusted valley.
The valley makes the Hat Creek site an ideal locale for listening to radio signals from space because the bowl-like enclosure effectively shields the dish array from humankind's ground-level radio broadcasts, Forster said.
Once the 42 dishes are up and running, astronomers will spend months calibrating them to avoid picking up signals from the many satellites orbiting earth, or even a distant NASA probe launched from Earth to scan the solar system, Forster said.
For practice, Forster said, the dishes that are currently installed and able to retrieve signals have been pointed at the probes, "listening" to the signals that bounce back.
The operation is not cheap. Each of the shiny dishes came with a $150,000 price tag, Forster said.
The array is named after Paul Allen, co-founder of Microsoft, who donated a large chunk of the $12.5 million construction costs, Forster said.
The hope is to eventually grow the site into a 350- or even a 500-dish array, a dream that could take years or possibly even decades to be realized because the operation is entirely funded by donations.
Hubbard told Reuters that more dishes are better when it comes to picking up a faraway or weak alien broadcast.
"You don't have to have somebody who is planning to broadcast a signal," Hubbard said. "You hope to pick up somebody's old radio broadcast that left a different planet hundreds or thousands of years ago."
Even if the Allen Array never once picks up a signal from another world, Forster said it's sky-scanning search will not be in vain. The fully-assembled array also will double as a massive radio telescope, capturing images of distant celestial bodies, he said.
Already, some of the recently installed dishes link together in small groups. They have captured some "marvelous" images of the Andromeda Galaxy, the Milky Way's nearest neighbor, Forster said.
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