A NEW planet a similar size to Earth has been discovered in our Solar System.
Astronomers believe they have found signs of a planet with a mass between that of Earth and Mars beyond Neptune.
The movement of objects in the Kuiper Belt, thousands of asteroids, comets and dwarf planets orbiting the Sun beyond Neptune, suggests a planet is hiding among them.
Neptune, the eighth planet in our Solar System, is the furthest from the Sun so far proven to exist.
Scientists claimed to have discovered a ninth planet beyond Neptune dubbed somewhat unimaginatively “Planet Nine”.
So if it’s existence is confirmed, the new planet would be the tenth world in our Solar System.
Only a heavenly body the size of Mars or bigger would have enough mass to alter the orbits of other objects in the Kuiper Belt, researchers at the University of Arizona's Lunar and Planetary Laboratory say.
Research fellow Kat Volk, of LPL, whose study will be published in The Astronomical Journal.
“According to our calculations, something as massive as Mars would be needed to cause the warp that we measured."
It is believed to be about 500 to 700 “astronomical units” from Earth – up to 65 trillion miles away.
Whatever is affecting the Kuiper Belt objects the researchers have spotted is much nearer.