Planet Found in 'Habitable' Zone 600 Light-Years Away

An Earth-like planet may be out there, according to the latest NASA Ames discovery. But don't pack your bags just yet.

NASA Ames announced today that its Kepler mission has confirmed the discovery of its first planet Kepler-22b in the "habitable zone," the region where liquid water could exist on a planet's surface. Kepler uses an astronomical telescope, which they point at one star for an entire mission, to observe when planets transit across the surface of that star.

"Fortune smiled upon us with the detection of this planet," said William Borucki, Kepler principal investigator at NASA Ames Research Center at Moffett Field, who led the team that discovered Kepler-22b. "The first transit was captured just three days after we declared the spacecraft operationally ready. We witnessed the defining third transit over the 2010 holiday season."

Kepler-22b, located 600 light-years away, measures about 2.4 times the radius of the Earth and has a 290 day orbit. It orbits a sun similar to our sun. NASA scientists have yet to determined the composition of the planet's surface.

"This is a major milestone on the road to finding Earth's twin," said
Douglas Hudgins, Kepler program scientist at NASA Headquarters in
Washington. "Kepler's results continue to demonstrate the importance of
NASA's science missions, which aim to answer some of the biggest questions
about our place in the universe."

In total, this current three and one half year Kepler mission has discovered more than 1,000 planet candidates, 10 similar to the Earth in size and distance from their host star. Investigations continue to determine planetary status.

Kepler discovers planets and planet candidates by measuring dips in the brightness of more than 150,000 stars to search for planets that cross in front, or "transit," the stars. Kepler requires at least three transits to verify a signal as a planet.