NASA's Kepler mission announced Wednesday the discovery of 715 new planets. These newly-verified worlds orbit 305 stars, revealing multiple-planet systems much like our own Solar System.
Nearly 95 percent of these planets are smaller than Neptune, which is almost four times the size of Earth. This discovery marks a significant increase in the number of known small-sized planets more akin to Earth than previously identified exoplanets, which are planets outside our Solar System.
The research team used a technique called verification by multiplicity, which relies in part on the logic of probability. Kepler observes 150,000 stars, and has found a few thousand of those to have planet candidates. If the candidates were randomly distributed among Kepler's stars, only a handful would have more than one planet candidate. However, Kepler observed hundreds of stars that have multiple planet candidates. Through a careful study of this sample, these 715 new planets were verified.
These multiple-planet systems are fertile grounds for studying individual planets and the configuration of planetary neighborhoods. This provides clues to planet formation.
This latest discovery brings the confirmed count of planets outside our Solar System to nearly 1,700. As we continue to reach toward the stars, each discovery brings us one step closer to a more accurate understanding of our place in the galaxy.
Read the full story on NASA's website.