SETI embarks on biggest-ever search for extraterrestrials

Posted by Emma Woollacott

The Search for Extraterrestrial Intelligence (SETI) is turning its focus once again on some of the stars that were its very first targets back in 1960.

For the last week, astronomers around the world have been looking out for radio and laser signals from civilizations circling stars including Tau Ceti and Epsilon Eridani.

"This will be the largest multinational SETI campaign ever attempted," says Gerry Harp, astrophysicist at the SETI Institute.

"Another unique quality is that these observations will be made across the electromagnetic spectrum from radio to optical frequencies, correlating near-simultaneous signals from the same stars. This is a new approach and lights the way for future SETI searches that cover all frequencies and all the sky, all the time."

The first SETI experiment, Project Ozma, was carried out fifty years ago by astronomer Frank Drake. Project Dorothy represents a continuation of that search.

"To have so many talented people using so many telescopes in this new search, with the electronics and computer equipment of today, is a joyful thing to me," says Drake. "The equipment of today is far better than what we could have fifty years ago, and will result in both very much better and very much more data than could be obtained then."

The SETI Institute is observing five target stars using the Allen Telescope Array (ATA), located in northern California.

“Two of the original stars from Project Ozma — Tau Ceti and Epsilon Eridani — are the nearest solar-type tars in the northern hemisphere. Therefore, these two stars were the best SETI targets a half century ago,” says team member Shin-ya Narusawa.

"But astronomy has improved over the last five decades, and about five hundred planets have been discovered around other stars. Some of these stellar systems have planets located the right distance from their stars to support life. We also included such stars among the targets of Project Dorothy."