On Monday, Jan. 07, 2013, NASA announced that the space agency’s Kepler Space Telescope had discovered a staggering 461 new possible planet candidates. Four of these are less than twice the size of Earth and exist within their parent star’s habitable zone (where liquid water could flow on the planet’s surface).
The Kepler team conducted studies spanning between May 2009 and March 2011. Kepler is increasingly finding smaller worlds. Moreover, it is finding stars that have more than just one planetary candidate.
“There is no better way to kick off 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 (Search for Extraterrestrial Intelligence), who is leading the study of the data gleaned from Kepler.
Since Kepler’s catalog was released in February of last year, the amount of possible planets discovered has jumped 20 percent—now totaling 2,740 worlds circling 2,036 distant suns. Worlds near the size of Earth or larger (dubbed super-Earths) have increased some 43 and 21 percent, respectively (according to a press release issued by NASA).
The findings mean that the number of stars found to have more than one possible planet circling them has increased from 365 to 467. To date, 43 percent of the candidates that Kepler has discovered are, more than likely, solar systems.
“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. “This is consistent with what we know about our own planetary neighborhood.”
Kepler uses a method where it studies the brightness of 150,000 different stars and watches to see if the light of those individual stars dims when a possible planet passes in front of that star. This is called “transiting,” and three transits have to be confirmed to verify a possible planet.
Researchers have reviewed the data from more than 13,000 possible “hits,” representing possible worlds. NASA then filters out possible false positives, such as astrophysical phenomena and spacecraft, to further verify that the discoveries are, in fact, exoplanets.
Before they are given the official nod as being deemed exoplanets, candidates undergo a screening process consisting of follow-up observations and study. Early last year some 33 possible planets were confirmed; today that number has soared to 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.”
For those interested in the numerous exoplanets, the list of all the possible planets that Kepler has found to date are available for review by the public online through NASA’s Interactive Exoplanet Archive. The archive was established to promote the goal of finding extrasolar planets with the public.
Kepler was launched from Cape Canaveral Air Force Station’s Space Launch Complex 17 located in Florida. The telescope took off on its seven-and-a-half-year mission in March 2009. NASA’s Jet Propulsion Laboratory in Pasadena, Calif., manages the space agency’s Exoplanet Exploration Program.
Video courtesy of NASA Television