Kepler Space Telescope Completes Prime Mission
November 15, 2012

Kepler To Begin New Extended Mission Through 2016

Lee Rannals for - Your Universe Online

As the Kepler Space Telescope's prime mission comes to an end after three-and-a-half years, its new extended mission will begin.

NASA's Kepler telescope has helped scientists identify more than 2,300 planet candidates, and confirm more than 100 plants.

The telescope is helping to unravel more information about the universe, and gather details about what lies beyond those stars in the sky.

Hundreds of Earth-size planet candidates have been found by Kepler that orbit in the habitable zone, which is the region in which liquid water may exist on the surface of a planet.

During its prime mission, Kepler collected enough data to begin finding true sun-Earth analogs, which are Earth-size planets with a one-year orbit around stars similar to the sun.

"The initial discoveries of the Kepler mission indicate at least a third of the stars have planets and the number of planets in our galaxy must number in the billions," said William Borucki, Kepler principal investigator at NASA's Ames Research Center in Moffett Field, California. "The planets of greatest interest are other Earths and these could already be in the data awaiting analysis. Kepler's most exciting results are yet to come."

Kepler is able to pick out planets around other stars by measuring the brightness of more than 150,000 stars. When a planet candidate passes in front of its host star, some light from the star is blocked.

NASA's telescope launched back in March of 2009, and its mission was to survey a portion of the galaxy to determine what fraction of stars might harbor potentially habitable, Earth-sized planets.

Within months of being commissioned, Kepler was able to help scientists confirm five exoplanets.

In August 2010, scientists using Kepler data confirmed the discovery of the first planetary system with more than one planet transiting the same star, which was the Kepler-9 system.

A few months later, in January 2011, the Kepler team announced the discovery of the first unquestionably rocky planet outside the solar system, Kepler-10b. This planet measured 1.4 times the size of Earth.

A month after that, scientists announced that the telescope helped find a crowded and compact planetary system featuring a star with multiple transiting planets. This system, known as Kepler-11, has six planets larger than Earth, all orbiting closer to their star than Venus orbits our sun.

In September 2011, NASA said Kepler discovered the mission's first planet in the habitable zone, Kepler-22b. This planet is about 2.4 times the size of Earth, and is the smallest-radius planet found to orbit a sun-like star in the habitable zone.

Earlier this year, the team announced more than 1,000 new transiting planet candidates, bringing the total to 2,321.

"Kepler's bounty of new planet discoveries, many quite different from anything found previously, will continue to astound," said Jack Lissauer, planetary scientist at Ames. "But to me, the most wonderful discovery of the mission has not been individual planets, but the systems of two, three, even six planets crowded close to their stars, and, like the planets orbiting about our sun, moving in nearly the same plane."

NASA awarded Kepler an extended mission through late 2016 back in April of this year, enabling the telescope more time to search for Earth-like planets.

"The Earth isn't unique, nor the center of the universe," said Geoff Marcy, professor of astronomy at the University of California at Berkeley. "The diversity of other worlds is greater than depicted in all the science fiction novels and movies. Aristotle would be proud of us for answering some of the most profound philosophical questions about our place in the universe."