New Earth-Like Planet Discovered by NASA’s Kepler Space Telescope

Astronomers using NASA’s Kepler Space Telescope announced Thursday the discovery of the most Earth-like planet yet orbiting a distant star like our own sun, bringing to a dozen the number of small worlds potentially suitable for life spotted elsewhere in the galaxy.

The newly discovered planet, called Kepler-452b, is the smallest to date found orbiting in the habitable zone of a distant star—the area where the water considered essential for life could exist.

Every 385 days, the planet circles a star slightly brighter than the sun, located about 1,400 light years away in the Constellation Cygnus, the researchers said.

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Based on available data, the planet is most likely rocky, about 60% larger than Earth and about 1.5 billion years or so older, the researchers said. So far, there is no evidence that it has an atmosphere. The researchers don’t know the planet’s mass, but speculated that its gravity may be twice that on Earth.

“It is a pretty good close cousin to our Earth and our sun,” said John Grunsfeld, associate administrator for science at the National Aeronautics and Space Administration in Washington, D.C. “It is the closest so far.”

The Kepler astronomers, however, have no direct evidence that the newly found planet can actually support life.

The space agency announced the find at a media briefing Thursday. A research paper reporting the conclusions has been accepted for publication in the Astronomical Journal.

The discovery was found by analyzing data on about 150,000 stars collected by the $600 million planet-hunting space telescope before it malfunctioned two years ago.

To help confirm the finding, astronomers also conducted ground-based observations at the University of Texas’ McDonald Observatory in Fort Davis, Texas; the Fred Lawrence Whipple Observatory on Mount Hopkins in Arizona; and the W.M. Keck Observatory on Mauna Kea in Hawaii.

The Kepler scientists said Thursday that they also have identified 521 new possible exoplanets, as worlds around other stars are called.

So far, the Kepler astronomers have confirmed the existence of 12 planets less than twice the size of Earth in the habitable zones of the stars they orbit.

All told, the researchers are analyzing data about 4,696 potential exoplanets and have confirmed the existence of 1,028 exoplanets of all sorts. A dozen of them appear to be between one to two times the size of Earth, and orbit in their star’s habitable zone. Of these, nine orbit stars that are similar to the sun in size and temperature, including the exoplanet announced Thursday.

“We are the breadcrumbs of the universe,” said Kepler research scientist Jeff Coughlin, from the SETI Institute in Mountain View, Calif. “Planets like Earth do appear to be quite common.”