They Beam From Outer Space?

If alien civilizations are beaming laser messages across the galaxy, The Planetary Society is about to increase the odds of finding them when it opens its new Optical SETI Telescope in Harvard, Massachusetts early in 2002. SETI stands for the search for extraterrestrial intelligence.

Designed to scan the sky for pulsed laser signals, the all-sky Optical SETI Survey will use a 1.8 meter (72 inch) diameter optical telescope dedicated exclusively to SETI. When completed, the new telescope will be the largest in the eastern United States. Professor Paul Horowitz of Harvard University is the project leader.

"Using only 'Earth 2001' technology, we could now generate a beamed laser pulse that appears 5000 times brighter than our sun, as seen by a distant civilization in the direction of its slender beam," said Horowitz. "In other words, interstellar laser communication is altogether practicable. The new Optical SETI Telescope will allow us to search the entire northern sky for such signs of intelligent life elsewhere in the galaxy."

Horowitz and his team have designed and ordered a custom telescope and broken ground on construction of an observatory in which to house it in Harvard, Massachusetts.

Once operational, the new optical SETI observatory will search for brief pulses of light, covering the entire northern sky once every 200 clear nights. Its special camera will stare at a stripe of sky with an array of 1024 ultrafast detectors, seeking flashes of light as short as a billionth of a second.

The Planetary Society is funding the project with a $350,000 grant, raised through contributions from its members. David Brown, a member of the Society's New Millennium Committee, is providing half the funds through a matching gift challenge to Society members.

This project will be the twelfth SETI project sponsored by the Society since the organization began in 1980. It is the latest in a long history of Society-supported SETI projects -- all with private funds -- which include several radio telescope searches and the internationally popular SETI@home project. Over 2.6 million SETI@home users have joined the quest for extraterrestrial intelligence, using their home computers to help process SETI data.

Professor Horowitz has worked on SETI projects with The Planetary Society for nearly two decades now. These include BETA, a radio telescope search in Harvard, Massachusetts; META in Argentina; and a search for laser communication from 13,000 selected stars.

Searching for narrowband laser pulse SETI signals was first suggested by Nobel prize winner Charles Townes of the University of California, Berkeley. Early optical SETI observations were made by Viktor Shvartsman, Albert Betz, and Stuart Kingsley. The current projects, with their advanced detectors, were recommended in a study conducted by the SETI Institute, which is helping to sponsor searches.