California: NASA scientists have announced the discovery of 715 new planets around distant stars including four alien worlds roughly the size of Earth with the potential for life. Using Kepler Space Telescope the data was collected over two years on 150,000 or so stars. This brings the count of planets outside our solar system to 1700. “We have almost doubled the number of planets known to humanity,” said planetary scientist Jack Lissauer, who is a science co-investigator on the $600 million Kepler space telescope mission.
The team of three dozen astronomers, data analysts and planetary scientists detailed their findings in two research papers submitted to the Astrophysical Journal and discussed their findings Wednesday at a news conference held by NASA.
Almost all of the newly verified exoplanets—as the alien worlds are called because they are outside our solar system—are smaller than Neptune, a gas giant at the outer reaches of the solar system that is almost four times the size of Earth. The worlds are clustered around just 305 stars in solar systems that, like our own, contain multiple planets, the scientists said.
The researchers said that four of these newly confirmed planets are less than 2.5 times the size of Earth, which means the force of gravity there would be relatively comfortable for creatures like humans, and orbit in the so-called habitable zone around their stars—the distance at which the surface temperature of an orbiting planet may be right for liquid water. It wouldn’t be so hot that it would boil and dissipate into space or so cold that it would freeze solid.
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