A San Francisco-based astronomer compiled swaths of data from researchers around the world to figure out which of more than 4,000 potential planets discovered during the NASA Kepler mission are likely to have the right climate to support life.
The research could help scientists focus their efforts to discover life beyond Earth and prepare for future planet-hunting missions. It was submitted to the Astrophysical Journal before summer and is slated for publication in the coming months.
Stephen Kane, the San Francisco State University professor of astrophysics who headed the international team, said in an interview Friday that researchers identified 20 planets within the habitable zone of a star that are rocky like Earth.
That means the planets could have liquid water on the surface, and therefore are the best candidates out of the Kepler bunch to find life, Kane explained.
But, “That doesn’t mean that we could go there and just take off our space helmets,” Kane said.
The planets are in the habitable zones of their stars, meaning water could exist there. However, Earth was in the habitable zone of the sun when it was 1 billion years old, yet humans could not have lived here at that time because of the lack of oxygen, Kane explained.
The Kepler Space Telescope launched in 2009 in search of new planets and is sending back data for researchers to use.
Over three years, the Kane and his team examined the properties of the stars and planets in the Kepler trove to determine which planets could have a climate too hot or too cold for water. They then produced an extensive report on 216 planets, including the 20 rocky ones, that are within the habitable zone of a star, sorting them into categories by planet size.
The planets are between 500 and 1,000 light years away in the Cygnus constellation, “which is still reasonably close” compared to the 100,000 light year diameter of the galaxy, Kane said.
In 2017, NASA plans to launch the Transiting Exoplanet Survey Satellite to look for planets like Kepler but closer to Earth than the Cygnus constellation. The following year, the James Webb Space Telescope will depart Earth and allow scientists to study the atmospheres of planets.
As for his most recent research, Kane said their catalogue of habitable-zone planets in the Kepler trove is a big deal.
“As much as we’d like to just point our telescopes at other planets and say, ‘Hey, there’s life,’ it’s another milestone that we’ve gotten to,” he said.
The team included researchers from NASA, Arizona State University, Caltech, University of Hawaii-Manoa, the University of Bordeaux, Cornell University and the Harvard-Smithsonian Center for Astrophysics, according to SFSU.