New mega-Earth discovery
A rocky planet dubbed a 'mega earth' has been discovered in a distant star system.
The planet, known as Kepler-10c, is so old that theoretically it should have become a 'Jupiter-like gas giant' – but has remained solid like Earth.
It is twice as old as Earth and has 17 times the mass, and its discovery suggests potentially life-bearing rocky planets could be far more abundant than previously thought.
Dr Dimitar Sasselov, from the Harvard-Smithsonian Centre for Astrophysics, said: "This is the Godzilla of Earths, but unlike the movie monster, Kepler-10c has positive implications for life. Finding Kepler-10c tells us that rocky planets could form much earlier than we thought. And If you can make rocks, you can make life."
The Kepler-10 star system is an estimated 11 billion years old, which means that it actually formed less than three billion years after the Big Bang. Earth is roughly 4.5 billion years old.
