NASA'S KEPLER MISSION DISCOVERS 461 NEW PLANET CANDIDATES
WASHINGTON -- NASA's Kepler mission Monday announced the discovery of
461 new planet candidates. Four of the potential new planets are less
than twice the size of Earth and orbit in their sun's "habitable
zone," the region in the planetary system where liquid water might
exist on the surface of a planet.
Based on observations conducted from May 2009 to March 2011, the
findings show a steady increase in the number of smaller-size planet
candidates and the number of stars with more than one candidate.
"There is no better way to kickoff the start of the Kepler extended
mission than to discover more possible outposts on the frontier of
potentially life bearing worlds," said Christopher Burke, Kepler
scientist at the SETI Institute in Mountain View, Calif., who is
leading the analysis.
Since the last Kepler catalog was released in February 2012, the
number of candidates discovered in the Kepler data has increased by
20 percent and now totals 2,740 potential planets orbiting 2,036
stars. The most dramatic increases are seen in the number of
Earth-size and super Earth-size candidates discovered, which grew by
43 and 21 percent respectively.
The new data increases the number of stars discovered to have more
than one planet candidate from 365 to 467. Today, 43 percent of
Kepler's planet candidates are observed to have neighbor planets.
"The large number of multi-candidate systems being found by Kepler
implies that a substantial fraction of exoplanets reside in flat
multi-planet systems," said Jack Lissauer, planetary scientist at
NASA's Ames Research Center in Moffett Field, Calif. "This is
consistent with what we know about our own planetary neighborhood."
The Kepler space telescope identifies planet candidates by repeatedly
measuring the change in brightness of more than 150,000 stars in
search of planets that pass in front, or "transit," their host star.
At least three transits are required to verify a signal as a
potential planet.
Scientists analyzed more than 13,000 transit-like signals to eliminate
known spacecraft instrumentation and astrophysical false positives,
phenomena that masquerade as planetary candidates, to identify the
potential new planets.
Candidates require additional follow-up observations and analyses to
be confirmed as planets. At the beginning of 2012, 33 candidates in
the Kepler data had been confirmed as planets. Today, there are 105.
"The analysis of increasingly longer time periods of Kepler data
uncovers smaller planets in longer period orbits-- orbital periods
similar to Earth's," said Steve Howell, Kepler mission project
scientist at Ames. "It is no longer a question of will we find a true
Earth analogue, but a question of when."
The complete list of Kepler planet candidates is available in an
interactive table at the NASA Exoplanet Archive. The archive is
funded by NASA's Exoplanet Exploration Program to collect and make
public data to support the search for and characterization of
exoplanets and their host stars.
Ames manages Kepler's ground system development, mission operations
and science data analysis. NASA's Jet Propulsion Laboratory (JPL) in
Pasadena, Calif., managed Kepler mission development. Ball Aerospace
and Technologies Corp. in Boulder, Colo., developed the Kepler flight
system and supports mission operations with JPL at the Laboratory for
Atmospheric and Space Physics at the University of Colorado in
Boulder.
The Space Telescope Science Institute in Baltimore archives, hosts and
distributes the Kepler science data. Kepler is NASA's 10th Discovery
Mission and is funded by NASA's Science Mission Directorate at the
agency's headquarters in Washington.
JPL manages NASA's Exoplanet Exploration Program. The NASA Exoplanet
Archive is hosted at the Infrared Processing and Analysis Center at
the California Institute of Technology.
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