Astronomers on Monday added 219 candidates to the growing list of planets beyond the solar system, 10 of which may be about the same size and temperature as Earth, boosting the chances for life.
"An important question for us is, 'Are we alone?'" Kepler program scientist Mario Perez said in a conference call with reporters.
"Understanding their frequency in the galaxy will help inform the design of future Nasa missions to directly image another Earth". All of Kepler's observations were in a small patch of sky between the constellations of Cygnus and Lyra. The 10 new exoplanets adds to the 49 nearly Earth-like exoplanets in habitable zones detected by Kepler, more than 30 of which have been verified.
Around 50 of the planets are a similar size to Earth and are in the so-called "Goldilocks zone" - a distance from their star that is not too hot and not too cold for water to present.
This artist rendering provided by NASA/JPL-Caltech/T. Pyle, taken in 2015, depicts one possible appearance of the planet Kepler-452b, the first near-Earth-size world to be found in the habitable zone of a star that is similar to our sun. Of which, 2,335 have been verified as exoplanets. Far from there being a continuum of planets, the study found two distinct groups: one smaller than 1.5 times the size of the Earth, the other bigger than twice Earth's size, with very few examples in the gap in between. "Both results have significant implications for the search for life", NASA reports. "It's wonderful the things that Kepler has found, it has shown us these terrestrial worlds, and we still have all this work to do to understand how common Earths are in the galaxy".
NASA said in a statement: "There are now 4034 planet candidates identified by Kepler".
The result: 4,034 exoplanet candidates.
So to fix this, the Kepler team simulated their own positive and false signals of planet transits and compared them to the actual data from the mission.
Until KOI-7711 is verified and earns an official Kepler planet name - a process that requires a different telescope (usually ground-based) to observe it transiting - this is all speculation.
With the final catalog of planetary candidates from Kepler's original mission released, NASA will now focus on the "K2" mission, which began in 2014. The team found a clean division in the sizes of rocky, Earth-size planets and gaseous planets smaller than Neptune. As it trailed behind Earth's on its yearly trip around the sun, Kepler constantly watched more than 160,000 stars for any hint of dimming.
"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.
Scientists were even able to estimate the size and density of the planets.