The number of known planets nearly doubled on Wednesday after NASA announced that it had found 715 planetary bodies orbiting distant stars. And some, the space agency says, may support life.
This most recent discovery was made by NASA’s Kepler mission, which is charged with identifying habitable Earth-sized planets. It brings the count of total known planets outside the solar system is about 1,700.
Since the first of these exoplanets was discovered about two decades ago, NASA has confirmed 961 to be “bonafide worlds” as the agency puts it, referring to planets that may sustain life.
Of the more than 700 new planets found on Wednesday, four fit Kepler’s criteria for sustaining life. According to the mission’s website, they are “less than 2.5 times the size of Earth and orbit in their sun’s habitable zone.”
The “habitable zone” is a term for the particular distance from a star at which liquid water can develop on a planet--a sweet spot for life to emerge. The size of the planet is relevant as a potential factor in determining whether it is gaseous or rocky, the latter being necessary to supporting life as we know it.
So is there life on any of these planets?
According to Lee Billings, the author of Five Billion Years of Solitude, a book detailing scientists’ quest for habitable planets, “the writing has been on the wall for years now. Essentially every star in the sky is accompanied by planets.” But limited funds have been devoted to identifying and studying their properties. “We haven’t made the investment to get better data,” he told Newsweek.
“The planets are out there,” Billings added. “The question is what are we going to do now?”