NASA on Tuesday said 1,284 new planets had been discovered by the Kepler space telescope, marking the biggest batch of exoplanets ever announced at one time.
Nine of the planets could potentially be habitable due to surface temperatures that would allow liquid water to pool, NASA added. The Kepler telescope, which launched in 2009, has now discovered 21 exoplanets with similar characteristics.
Kepler is the first NASA mission to find potentially habitable Earth-size planets.
"This gives us hope that somewhere out there, around a star much like ours, we can eventually discover another Earth," Ellen Stofan, chief scientist at NASA headquarters in Washington, D.C. said in a statement.
The recent discoveries more than double the number of exoplanets — planets outside our solar system — that have been discovered by Kepler. There are now 3,264 known exoplanets, 2,325 of which were found by Kepler.
In addition to the 1,284 new planets announced on Tuesday, the Kepler telescope discovered 1,327 so-called candidates that, once verified, could be confirmed planets. NASA classifies a candidate a planet only when the probability of it being so is greater than 99%. The 1,327 candidates do not meet that threshold, so more research is needed.
"Before the Kepler space telescope launched, we did not know whether exoplanets were rare or common in the galaxy," Paul Hertz, director of Astrophysics Division at NASA, said in a statement. "Thanks to Kepler and the research community, we now know there could be more planets than stars. This knowledge informs the future missions that are needed to take us ever closer to finding out whether we are alone in the universe."