NASA’s Kepler Space Telescope continues to stun as officials at the U.S.-based space agency announced the discovery of nearly 500 new planets.
Officials at NASA announced the findings late Monday, saying the space telescope had discovered 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.
Kepler, which recently began its extended mission, has already successful completed a 3 1/2 year prime mission. The new extended mission could last as long as four years, according to NASA.
“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, California, who leads the project.
So far, hundreds of Earth-size planet candidates have been discovered by the space telescope. Kepler has also discovered a number of potential planets that orbit in the habitable zone, the region in a planetary system where liquid water might exist on the surface of a planet. None of the candidates is exactly like Earth. With the completion of the prime mission, Kepler has now collected enough data to begin finding true sun-Earth analogs — Earth-size planets with a one-year orbit around stars similar to the sun.
The announcement comes as a pair of studies have concluded that the Milky Way hosts upwards of 100 billion planets orbiting their own respective star systems. The study is widely viewed as the first attempt to accurately estimate the number of total planets within our own galaxy and could spur additional research to better narrow the number.
“There are at least 100 billion planets in the galaxy, just our galaxy,” says John Johnson, assistant professor of planetary astronomy at Caltech and coauthor of the study, which was recently accepted for publication in the Astrophysical Journal. “That’s mind-boggling.”
“It’s a staggering number, if you think about it,” added Jonathan Swift, a postdoctoral student at Caltech and lead author of the paper. “Basically, there’s one of these planets per star.”
The Kepler mission looks out at a vast field of more than 150,000 stars, scanning for the periodic dimming in their light that might indicate orbiting planets are crossing in front of them, also known as transiting. On Monday, NASA said Kepler has detected 2,740 candidate planets orbiting 2,036 stars. To date, 105 of the candidate planets have been confirmed by astronomers around the world.