Starry nights go digital for planet-hunter

WASHINGTON (Reuters) - Geoff Marcy has looked at 85 different stars this evening, but he has yet to actually see a single one of them.

The giant Keck telescope he is using, on the summit of Hawaii's Mauna Kea volcano, is sending images straight to a digital camera, to be analyzed by a computer.

"There are no eyepieces anywhere. In fact, we don't have an eyepiece for the Keck telescope," Marcy, an astronomy professor at the University of California, Berkeley, said in a telephone interview as he finished up a night of planet-hunting.

"Some of the romance of astronomy is gone."

Centuries ago, Galileo Galilei peered through a small, simple telescope to draw his pictures of four of Jupiters' moons: Io, Callisto, Europa and Ganymede, as did Giovanni Schiaparelli, who spotted the "canali" (channels) on Mars.

Marcy does not peer, and his methods are far more efficient than those of his predecessors.

"We've done about 85 stars tonight," Marcy said. "We started at about 6 p.m. and it is 4:30 a.m. now. We never stop and we never take any breaks. The world's largest telescope is so precious that you don't want to waste a second."

Marcy is in fact not even sitting at the telescope. The eight-story telescope is a 45-minute drive away, in the thin air above 13,000 feet.

He is connected by audio and video link to a telescope operator who points and clicks at his command.

The $100 million telescope collects the light from stars and sends them straight to a spectrometer that, like a prism, separates light into its colored wavelengths.

"It goes to a digital camera, the spectrum is recorded, and I take it back to the University of California Berkeley to get all the data," said Marcy.

Using this method, Marcy's team has discovered 28 new planets orbiting other stars in the past year. They are responsible for two-thirds of the 236 known exoplanets.

But it can be frustrating to work so indirectly.

A cloud can wreak havoc on a night of observing booked months in advance and amid the clamoring demands of other astronomers.

"Tonight, for example, there are 15 or 20 stars I had my heart set on that we won't get to observe. The sky is a big place so I have to make sure that the telescope doesn't have to move too far."

Most of the planets seen so far are gas giants like Jupiter, unlikely to host life. But astronomers hope to refine their methods so they can spot small, rocky planets covered with liquid water, like our own.

"The real question that is on everybody's minds, whether you are 6 years old or 96, is whether there is intelligent life in the universe," Marcy said. "We will point our telescopes at those Earths hoping to pick up transmissions from any intelligent species that might happen to be living there.

"Hopefully they have progressed beyond 'I Love Lucy.'"