NASA's Kepler Discovers Five New Exoplanets
Launched in March of last year, NASA's Kepler telescope has discovered its
first five new planets beyond Earth's solar system. Known as exoplanets, the
Kepler discoveries are also called "hot Jupiters" because of their
high masses and extreme temperatures.
The new exoplanets range in size from similar to Neptune to larger than Jupiter and have orbits ranging from 3.3 to 4.9 days. Estimated temperatures of the planets range from 2,200 to 3,000 degrees Fahrenheit. All five of the exoplanets orbit stars hotter and larger than Earth's sun.
The discoveries were announced Jan. 4 by the members of the Kepler science team during a news briefing at the American Astronomical Society meeting in Washington.
"These observations contribute to our understanding of how planetary systems form and evolve from the gas and dust disks that give rise to both the stars and their planets," said William Borucki of NASA's Ames Research Center in Moffett Field, Calif. "The discoveries also show that our science instrument is working well. Indications are that Kepler will meet all its science goals."
Since its launch, the Kepler mission has continuously observed more than 150,000 stars. Kepler's science instrument, or photometer, already has measured hundreds of possible planet signatures that are being analyzed.
According to NASA, while many of these signatures are likely to be something other than a planet (such as small stars orbiting larger stars), ground-based observatories have confirmed the existence of the five exoplanets. The discoveries are based on approximately six weeks' worth of data collected since science operations began on May 12.
"It's gratifying to see the first Kepler discoveries rolling off the assembly line," said Jon Morse, director of the Astrophysics Division at NASA headquarters in Washington. "We expected Jupiter-size planets in short orbits to be the first planets Kepler could detect. It's only a matter of time before more Kepler observations lead to smaller planets with longer period orbits, coming closer and closer to the discovery of the first Earth analog."
NASA officials said Kepler will continue science operations until at least November 2012, searching for planets as small as Earth, including those that orbit stars in a warm habitable zone where liquid water could exist on the surface of the planet. Since transits of planets in the habitable zone of solarlike stars occur about once a year and require three transits for verification, it is expected to take at least three years to locate and verify an Earth-size planet.
"Today's discoveries are a significant contribution to that goal," Borucki said. "The Kepler observations will tell us whether there are many stars with planets that could harbor life, or whether we might be alone in our galaxy."