By Brandon Moseley
Alabama Political Reporter
Are we alone in the universe? Nobody knows the answer to that but there are billions of stars and according to new analysis by NASA there may even be more planets. On Tuesday, May 10 NASA revealed that they have used the Kepler Space Telescope to identify 4,302 potential planets most of them not previously known to astronomers.
Of those, NASA was able to verify 1,284. There are another 1,327 that are likely planets but NASA has not yet compiled enough evidence to verify that yet. 707 were ruled to be other astrophysical phenomena and not actual planets. Kepler also validated the findings of previous missions on 984 other planets.
The Chief Scientist at NASA headquarters in Washington Ellen Stofan said in a statement, “This announcement more than doubles the number of confirmed planets from Kepler. This gives us hope that somewhere out there, around a star much like ours, we can eventually discover another Earth.”
The Astrophysics Division Director at NASA headquarters, Paul Hertz said, “Before the Kepler space telescope launched, we did not know whether exoplanets were rare or common in the galaxy. 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.”
Kepler is able to capture the discrete signals of distant planets transiting in front of their stars. That decreases in brightness that occurs when a planet travels in orbit between us and the front of its star is how scientist is able to detect the presence of distant planets. The first planets outside our solar system were only discovered a little more than two decades ago. Since then researchers have resorted to a laborious, one-by-one process of verifying suspected planets.
Scientists with the Kepler mission are using a new statistical analysis method that can be applied to many planet candidates simultaneously.
Timothy Morton, an associate research scholar at Princeton University in New Jersey, is the lead author of the scientific paper published in The Astrophysical Journal, describes how the team employed a technique to assign each Kepler candidate a planet-hood probability percentage – the first such automated computation on this scale, as previous statistical techniques focused only on sub-groups within the greater list of planet candidates identified by Kepler.
Morton said, “Planet candidates can be thought of like bread crumbs. If you drop a few large crumbs on the floor, you can pick them up one by one. But, if you spill a whole bag of tiny crumbs, you’re going to need a broom. This statistical analysis is our broom.”
Of the new planets, 550 are believed to be rocky planets like Earth. Nine of these orbit in their sun’s habitable zone, which is the distance from a star where orbiting planets can have surface temperatures that allow liquid water to pool. That takes the total number of known exoplanets in the habitable zone of their stars to 21. In our solar system Earth, Venus, and Mars are the only three planets in our sun’s habitable zone though only one of these, Earth, is known to support any life.
Natalie Batalha, who co-authored the paper, said, “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). This work will help Kepler reach its full potential by yielding a deeper understanding of the number of stars that harbor potentially habitable, Earth-size planets — a number that’s needed to design future missions to search for habitable environments and living worlds.”
Batalha is a scientist at NASA’s Ames Research Center in Moffett Field, California.
Almost 5,000 total planet candidates have been found to date. Of those more than 3,200 now have been verified, and 2,325 of these were discovered by Kepler. Kepler was launched in March 2009 and is the first NASA mission to find potentially habitable Earth-size planets. For four years, Kepler monitored 150,000 stars in a single patch of sky, measuring the tiny, telltale dip in the brightness of a star that can be produced by a transiting planet. In 2018, NASA’s Transiting Exoplanet Survey Satellite will use the same method to monitor 200,000 bright nearby stars and search for planets, focusing on Earth and Super-Earth-sized.
