Space: astronomers suggest there could be an Earth-like planet hiding in the Kuiper Belt

Two scientists have found likely evidence of a planet hiding our Solar System, just beyond Neptune.

The planet is Earth-sized, on a titled orbit that may be circling the Sun and much closer than the hypothetical Planet Nine thought to exist in the far outer edges of the Solar System.

Physicists, including those from the National Astronomical Observatory of Japan investigated trans-Neptunian objects (TNOs) and weird clustering behaviour and published their paper in The Astronomical Journal. 

They found that some of the objects in the Kuiper Belt, a group of icy rocks and dwarf planets, including Pluto, Quaoar, Orcus and Makemake, behave in a way suggesting the presence of a small planet among them.

Some of these rocks were found to have “odd” orbits suggesting they are being pulled by the gravity of a larger cosmic entity.

The planet would be about 250 - 500 astronomical units (AU) from the Sun - 1 AU is the distance between the Sun and the Earth, and 1.5-3 times the size of Earth, and a tilt of around 30 degrees. 

The most likely explanation for the observations, after the scientists ran computer simulations, would be that there is another hidden planet in the Kuiper Belt.

The researchers said: “We predict the existence of an Earth-like planet.

“It is plausible that a primordial planetary body could survive in the distant Kuiper Belt as a Kuiper Belt planet (KBP), as many such bodies existed in the early solar system."

Researchers say the discovery of such a planet close to the Kuiper Belt can unravel new constraints on planet formation and evolution.

“In conclusion, the results of the KBP scenario support the existence of a yet-undiscovered planet in the far outer solar system,” scientists noted.