Using a new verification technique, Kepler scientists have confirmed the existence of 715 new exoplanets — four of which are located within their star's habitable zone. It's the single largest windfall of new confirmations at any one time.
NASA made the stunning announcement earlier today at a news teleconference. Presenters included NASA scientists Douglas Hudgins and Jack Lissauer, who were joined by SETI's Jason Rowe and MIT's Sara Seager.
Validation by Multiplicity
Prior to today's announcement, planetary scientists had confirmed the existence of about 1,000 exoplanets. So, overnight, that figure jumps by a factor of 70% to 1,715.
It's important to note that confirmed planets are not the same thing as planetary candidates. It takes considerable time and effort to verify that candidates — the vast majority of which are detected using the transmit method (the tell-tale signature of a far-away planet as it briefly dims the light of its parent star as it passes in front of it) — are in fact actual planets and not some kind of celestial anomaly or data glitch.
But these 715 planets are no longer mere candidates, they're all totally legit — the result of a new technique called "validation by multiplicity." The method only works for solar systems in which multiple planets orbit around a single star, and in which the transit method yields consistent results. Multiple star systems are far too chaotic and unpredictable to produce such data — they don't look anything like standard solar systems. It's this fundamental assumption that forms the basis of the new validation technique. As Lissauer noted during the teleconference, it "provided the additional crucial evidence."
By applying the new method, the validation bottleneck was significantly reduced, allowing the Kepler scientists to make this sweeping one-time confirmation. And amazingly, these results are based on the first two years of Kepler data. There's another two years to analyze, which means there's a lot more to come. As Seager noted, "Kepler is the gift that keeps on giving." And the space telescope certainly appears ready to keep on giving.