Planet Search Getting Easier

H O N O L U L U,   Jan. 29 -- For millennia, man-kind has pondered and searched for worlds outside oursolar system — for planets like Earth that could support life.

But since the advent of modern astronomy centuries ago, detection of distant planets has proved to be as difficult as finding grains of sugar on a beach. Stars, billions of times more brilliant than the worlds that circle them, make planets all but impossible to find. And decades of intense observation yielded only false alarms, earning planet-hunting a reputation as a backwater of astronomy.

During the past three years, however, this perception has radicallychanged. Through advances in technology, an improved understanding ofplanetary behavior, and increased access to better telescopes, astronomershave found 17 planets since 1995. These discoveries have revolutionizedplanetary science, forcing scientists to revise long-held theories aboutthe universe and making planet-searching one of the hottest fields ofastronomy.

More Light Caught By Bigger Eyes

“The major change has been access to large telescopes like the Keck [atelescope in Hawaii with a mirror 30 feet across],” says William Cochran,an astronomer at the University of Texas at Austin. “With big scopes, youget a lot more light. And the faster you can get light, the faster you candetect these planets.”

In many ways, the recent discovery of what could be a nascent solar system220 light-years from Earth is a symbol of this planet-hunting renaissance.Images of the would-be solar system were first captured by the Kecktelescope. Later, using the Hubble Space Telescope, University of Hawaiiastronomer Bradford Smith discovered that there might be a planet withinthe new solar system. He found the planet by searching the heavens in adifferent way — by looking at disks of dust around stars.

Image Sifting Finds Ringed Object

He sifted infrared images of the star 220 light years away, dubbed HR4796A.

Inside its disk sat a ring that looked like hula hoop. “When wepulled the image of this star ring up on the computer screen, it lookedlike Saturn,“ says Dr. Smith. “It was like, ‘Wow!’ We had not reallyexpected that.“