Prof Goes High-Tech in ET Search

If alien civilizations light-years away are sending us messages coded in pulses of light, Professor of Physics and Electrical Engineering Paul Horowitz ’65 will be one of the first to know.

The Planetary Society, a leading non-profit space research organization, announced Tuesday that Horowitz will direct a year-long project to scan the Milky Way for light signals sent by extraterrestrial life using a new optical telescope at the Oak Ridge Observatory in Harvard, Mass.

The telescope, which was dedicated in a ceremony Tuesday, is the largest optical telescope east of the Mississippi, and is the first of its kind to be devoted entirely to the Search for Extra-Terrestrial Intelligence (SETI), according to the Planetary Society.

“It’s overwhelmingly likely—a certainty—that there’s other life in our galaxy,” Horowitz said yesterday. “There’s a pretty good likelihood that much of that life has evolved to a technological state.”

According to Bruce Betts, the Planetary Society’s director of projects, aliens who are only as technologically advanced as we are could be sending brief optical signals across the galaxy.

“With Earth technology 2006, we can transmit pulse lasers that outshine the sun by a factor of 10,000, but you have to look very quickly,” Betts said in a phone interview Tuesday.

Most SETI work has focused on detecting messages encoded in microwave emissions, according to Horowitz. But he said that aliens might use optical messages. Radiation at frequencies that fall into visible-light segment of the electromagnetic spectrum is easy to generate and detect, moves through the space fairly easily, and can encode large amounts of information, Horowitz said.

Betts said astronomers had been ill-equipped to receive such a signal until the installation of the new telescope Tuesday, which can detect a billionth-of-a-second flash of light.

“There have been small targeted searches, but with this setup...they’ll be able to cover the whole sky, increasing their sky coverage by a factor of 100,000,” Betts said.

According to Horowitz, the 72-inch telescope cost only $50,000 because it does not provide as sharp a picture as most astronomical projects require. However, the device is equipped with 1,024 light sensors that make a trillion measurements per second.

Horowitz said that he and his team, made up of Harvard undergraduates, graduate students, and one volunteer, would begin nightly searches in about two weeks.

The search for alien life is gaining increasing respect throughout the academic community, Horowitz said.

“Contact will be made someday, and when it happens it will be a bridge across 4 billion years of isolation,” Horowitz said. “It will be the greatest discovery ever made. How can you not consider that academically worthwhile?”

Horowitz’s previous searches have produced nothing definitive, although he said there have been some “heart-stoppingly close calls.”

However, he said that if one assumes the existence of extraterrestrial life, even a negative result can provide useful insight, narrowing down the list of possible ways aliens might be communicating with us.

While this might seem like a comforting consolation prize, Horowitz said he was reluctant to settle.

“I’d like to go the other way,” he said. “I’m taking a long shot and I’d like to succeed.”

—Staff writer Laurence H. M. Holland can be reached at lholland@fas.harvard.edu.