Planet twice the size of earth made of diamond
First known rocky planet 'fundamentally different' from our planet orbits Sun-like star
Forget the diamond as big as the Ritz. This one's bigger than planet Earth.
Astronomers have discovered a planet twice the size of our own made largely out of diamond, orbiting a star that is visible to the naked eye.
The planet, called "55 Cancri e", orbits a sun-like star in the constellation of Cancer and is moving so fast that a year there lasts a mere 18 hours.
Discovered by a US-Franco research team, its radius is twice that of Earth's but it is much denser, with a mass eight times greater.
It is also incredibly hot, with temperatures on its surface reaching 1,648 degrees Celsius.
"The surface of this planet is likely covered in graphite and diamond rather than water and granite," said Nikku Madhusudhan, the Yale researcher whose findings are due to be published in Astrophysical Journal Letters.