NASA’s catalog of potential planets just got 219 new additions, 10 of which are near-Earth size and might be habitable.
The Kepler space telescope team announced the discoveries Monday morning during a NASA press conference, calling this “the most comprehensive and detailed” catalog release of candidate exoplanets. They found they fall into two distinct size groupings and that both results have “significant implications for the search for life.”
“The Kepler data set is unique, as it is the only one containing a population of these near Earth-analogs, planets with roughly the same size and orbit as Earth,” said Mario Perez, Kepler program scientist in the Astrophysics Division of NASA’s Science Mission Directorate. “Understanding their frequency in the galaxy will help inform the design of future NASA missions to directly image another Earth.”
With the release of this catalog—derived from data publicly available on the NASA Exoplanet Archive—there are now 4,034 planet candidates identified using the Kepler telescope, which hunts for planets by detecting the minuscule drop in a star’s brightness during transit (when a planet crosses in front of it). Of these candidates, 2,335 have been verified as exoplanets (planets outside Earth’s solar system), and roughly 50 have been detected in habitable zones, meaning they’re in the range of distance from a star where liquid water could pool on the surface of a rocky planet.
This is the eighth release of the Kepler candidate catalog, and the data will enable scientists to determine which types of planets make up the galaxy’s planetary demographics.
“This carefully-measured catalog is the foundation for directly answering one of astronomy’s most compelling questions: how many planets like our Earth are in the galaxy?” said Susan Thompson, Kepler research scientist for the SETI Institute in Mountain View, California and lead author of the catalog study.
The team found that the planet candidates are either rocky and Earth-sized or gaseous and smaller than Neptune. Few planets were found between those groupings.
“We like to think of this study as classifying planets in the same way that biologists identify new species of animals,” said Benjamin Fulton, doctoral candidate at the University of Hawaii in Manoa and lead author of the second study. “Finding two distinct groups of exoplanets is like discovering mammals and lizards make up distinct branches of a family tree.”