NASA Takes Giant Step Toward Finding Earth-Like Planets

On a crystal clear, star-filled night at Hawaii's Keck Observatoryin Mauna Kea, NASA engineers successfully suppressed the blinding lightof three stars, including the well-known Vega, by 100 times. Thisbreakthrough will enable scientists to detect the dim dust disks aroundstars, where planets might be forming. Normally the disks are obscuredby the glare of the starlight.

Engineers accomplished this challenging feat with the KeckInterferometer, which links the observatory's two 10-meter (33-feet)telescopes. By combining light from the telescopes, the KeckInterferometer has a resolving power equivalent to a football-fieldsized telescope. The "technological touchdown" of blocking starlightwas achieved by adding an instrument called a "nuller."

This setup may eventually help scientists select targets for NASA'senvisioned Terrestrial Planet Finder missions. The success of thosepotential future missions, one observing in visible light and one ininfrared, depends on being able to find Earth-like planets in the dustrings around stars.

"We have proven that the Keck Interferometer can block light fromnearby stars, which will allow us to survey the amount of dust aroundthem," said Dr. James Fanson, project manager for the KeckInterferometer at NASA's Jet Propulsion Laboratory. That survey willbegin in late 2006 after the team refines the nuller's sensitivitylevel.

Combined information from all of NASA's planet-hunting missions willprovide a complete picture of possible Earth-like planets: how big theyare, whether they are warm enough for life, and if their atmospheresand surfaces show chemical signatures of current life.

"People have been talking about whether there are other earths outthere for 2,500 years. Only now are we developing the technology to gofind out," said Michael Devirian, manager of NASA's Navigator Programat JPL, which is investigating potential planet-exploring missions.

So far, scientists around the world have found 150 planets orbitingother stars. Most are giants, like Jupiter; none is as small as Earth.Scientists believe the best odds of finding life outside our solarsystem are on Earth-sized planets, particularly those with the righttemperature, density and chemistry.

More information on NASA's planet-finding missions, including the Keck Interferometer and Terrestrial Planet Finder is at http://planetquest.jpl.nasa.gov.

JPL manages the Keck Interferometer and the Terrestrial PlanetFinder missions for NASA's Science Mission Directorate, Washington. JPLis a division of the California Institute of Technology in Pasadena.The W.M. Keck Observatory is funded by California Institute ofTechnology, the University of California and NASA, and is managed bythe California Association for Research in Astronomy, Kamuela, Hawaii.