Astronomers Discover a Mega-Earth in the Constellation Draco

Posted on June 2, 2014

Astronomers have announced the discovery of a new type of planet called a Mega-Earth. The exoplanet is located 560 light-years away in the constellation Draco. The rocky world, Kepler-10c, weighs 17 times as much as the Earth. Researchers from the Harvard-Smithsonian Center for Astrophysics (CfA) say the new type of planet defies theories that predicted a world like this would be unable to form. It was believed that a planet would instead become a Jupiter-like gas giant as it tried to form, but researchers say this dense planet is "all solids."

CfA researcher Dimitar Sasselov calls the planet the "Godzilla of Earths" in the announcement. Sasselov says, "But unlike the movie monster, Kepler-10c has positive implications for life."

Kepler-10c circles its star every 45 days. It has a diameter of 18,000 miles, which is 2.3 times as large as Earth. The planet's solar system also includes a lava world, Kepler-10b, that has a 20-hour orbit. The above artist's conception shows Kepler-10c and its lava world sibling, Kepler-10b.

The researchers expert more mega-Earths will be discovered. The Kepler-10c system is 11 billion years old, which means rocky planets were able to form earlier than previously thought. The astronomers say the finding suggests old stars should not be ruled out when searching for Earth-like planets.

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