ET, Flash Home: New Telescope to Seek Alien Light Signals

Adrianne Appel
for National Geographic News

April 21, 2006

A massive new telescope will soon begin scanning the skies for laser flashes from extraterrestrials.

Researchers are focusing on laser light because they think advanced intelligent beings would use it to communicate with us, rather than the far more primitive radio signal (related: "Alien Contact More Likely by 'Mail' Than Radio, Study Says" [2004]).

"Pulse lasers allow the sending of very bright light very far, very quickly," said Bruce Betts. Betts is a planetary scientist and director of programs at the Pasadena, California-based Planetary Society, which funded the new telescope.

The telescope was custom-built for detecting extraterrestrials. It's the biggest optical telescope east of the Mississippi and is the first optical telescope devoted exclusively to the search for extraterrestrial intelligence.

The Optical SETI (search for extraterrestrial intelligence) telescope sits in a farmhouse-like structure in rural Massachusetts, 40 miles (65 kilometers) away from the Harvard University campus in Cambridge.

When the telescope is up and running, a Harvard team will operate it remotely from campus, said team leader Paul Horowitz, a physics professor at the university.

In the past five years the team—using a much less powerful telescope, which scanned just a fraction of the sky—has noted more than a hundred "events," Horowitz said.

Because of the limitations of the equipment, the team was unable to determine if the events were actual communications.

"We have no idea if there really are aliens. The next question would be, If there are aliens, can we detect it? The answer is yes. With this telescope we now have a much better chance," Betts said.

Talk or Just Chatter?

The telescope will note any light signals that are 10,000 times brighter than a star and that pulse for at least a few billionths of a second.

This measure was chosen because it reflects what we on Earth are capable of sending, Betts said.

If the telescope detects a flash, the apparatus will send information about the exact time and location of the light to its powerful computer.

Horowitz's team will review the data and decide if any flashes bear investigation. If so, the Harvard team will then ask another team to corroborate the sighting.

The telescope sports a 6-foot (183-centimeter) reflecting mirror and is so powerful it will be able to scan the entire sky of the Milky Way (see photo) over 200 clear nights. This is roughly equivalent to scanning all the books in print, every second.

What enables its powerful data processing capability are the 32 electronic chips that were "handmade" for the telescope by a graduate-student team member.

No Blinking Allowed

If the telescope detects a signal that the team believes comes from an alien population, scientists have no protocol for whether and how to respond. Horowitz's team won't respond themselves, he said.

"We're not sending anything and never have,'' Horowitz said. As far as any aliens are concerned, there is probably a proper way to respond, and we do not know what that is, he adds.

Any life-forms that would send signals would likely be very different from us, says Carol Cleland, an associate professor of philosophy at the University of Colorado at Boulder.

It all makes her slightly skeptical. "How do we search for life as we don't know it?'' she said.

A few glitches need to be squared away before the telescope goes fully online.

For example, if the observatory's roof is left open during the day, the heat generated by sunlight on the telescope creates what Harvard's Horowitz called "the world's biggest oven.

"We could burn the place down," he said

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