Today, Microsoft co-founder Paul Allen will join scientists from SETI – the Search for Extraterrestrial Intelligence – to unveil the first major telescope devoted full time to answering the question: Is anyone out there?

The first mission for the Allen Telescope Array will be to scan several billion stars across a vast swath of our own Milky Way galaxy, said astronomer Seth Shostak, of the SETI Institute in Mountain View, Calif. That broad-brush survey will be followed in the coming years by detailed examinations of a million stars — a quantum leap in coverage of celestial real estate. In the 45 years since scientists first started looking for signals from alien worlds, only about 750 stars have gotten such close scrutiny.

“This is an exponential increase in speed,” Shostak said. “And it covers much more of the radio dial, which is important because ET never told us where to look for his broadcasts.”