Artist renderings of exoplanets previously detected by the Kepler Space Telescope (NASA)
In the biggest haul ever of new exoplanets, scientists with NASA’s Kepler mission announced the confirmation of 1,284 additional planets outside our solar system — including nine that are relatively small and within the habitable zones of their host stars. That almost doubles the number of these treasured rocky planets that orbit their stars at distances that could potentially support liquid water and potentially life.
Prior to today’s announcement, scientists using Kepler and all other exoplanet detection approaches had confirmed some 2,100 planets in 1,300 planetary systems. So this is a major addition to the exoplanets known to exist and that are now available for further study by scientists.
These detections comes via the Kepler Space Telescope, which collected data on tiny decreases in the output of light from distant stars during its observing period between 2009 and 2013. Those dips in light were determined by the Kepler team to be planets crossing in front of the stars rather than impostors to a 99 percent-plus probability.
As Ellen Stofan, chief scientist at NASA Headquarters put it, “This gives us hope that somewhere out there, around a star much like ours, we can eventually discover another Earth.”
The histogram shows the number of planet discoveries by year for more than the past two decades of the exoplanet search. The blue bar shows previous non-Kepler planet discoveries, the light blue bar shows previous Kepler planet discoveries, the orange bar displays the 1,284 new validated planets.
(NASA Ames/W. Stenzel; Princeton University/T. Morton)
The primary goals of the Kepler mission are to determine the demographics of exoplanets in the galaxy, and more specifically to determine the population of small, rocky planets (less than 1.6 times the size of Earth) in the habitable zones of their stars. While orbiting in such a zone by no means assures that life is, or was, ever present, it is considered to be one of the most important criteria.
The final Kepler accounting of how likely it is for a star to host such an exoplanet in its habitable zone won’t come out until next year. But by all estimations, Kepler has already jump-started the process and given a pretty clear sense of just how ubiquitous exoplanets, and even potentially habitable exoplanets, appear to be.
“They say not to count our chickens before they’re hatched, but that’s exactly what these results allow us to do based on probabilities that each egg (candidate) will hatch into a chick (bona fide planet),” said Natalie Batalha, co-author of the paper in the Astrophysical Journal and the Kepler mission scientist at NASA’s Ames Research Center.… Read more
