An extremely distant dwarf planet, named The Goblin, has been discovered in observations that are redefining the outer reaches of the solar system.The new dwarf planet’s formal name, assigned by the International Astronomical Union’s Minor Planet Center, is 2015 TG387.

Orbit of Goblin

The newly discovered icy world, estimated to be just 300km across, is in an extremely elongated orbit. At its closest, it gets about two and a half times as far from the sun as Pluto. Then it heads off to the outermost fringes of the solar system, to almost 60 times further out than Pluto, taking an astounding 40,000 years to loop once around the sun. For 99% of its orbit, it would be too faint to see.

Third minor planet in outer solar system

The object is the third minor planet to have been found in the outer solar system, following the discoveries of Sedna and, recently, another object called 2012 VP113. And this region, which once appeared to be cold, dark and empty now appears to be a rich collection of exotic and extreme objects.

Intriguingly the orbits of the three objects discovered so far appear to be clustered together, suggesting that they are being shepherded by a giant, unknown object. This has pointed astronomers to the existence of a ninth, super-Earth sized planet.

Planet Nine

Astronomers made the discovery while hunting for a hypothetical massive planet, known as Planet Nine, that is suspected to be in orbit far beyond Pluto in a mysterious region known as the Oort Cloud. Planet Nine has not yet been seen directly, but The Goblin appears to be under the gravitational influence of a giant unseen object, adding to astronomers’ certainty that it is out there.

Estimated to be 10 times as massive as Earth,Planet Nine has been predicted in a series of studies over the years. It is believed to be influencing the behaviour of many known objects — behaviour that would be difficult to explain if it did not exist-

1 . In 2016, CalTech researchers Konstantin Batygin and Michael Brown argued that Planet 9 could be responsible for the peculiar alignment of objects on the outskirts of the Solar System.

2 . The same year, another team held Planet Nine responsible for the “wobble” in the orbital plane of the eight planets, which is aligned six degrees off from the Sun’s equatorial plane.

3 . Earlier this year, University of Michigan PhD student Juliette Becker and colleagues reported a new discovery — an object called 2015 BP519 — and argued that Planet 9 was causing the extreme tilt of BP519’s orbital plane, aligned at 54° to the orbital plane of the eight planets.


The discovery was made using the Japanese Subaru 8-metre telescope located on the dormant Mauna Kea volcano in Hawaii. The telescope is the only one in the world to be able to produce deep images capable of probing the outer reaches of the solar system, while also having a wide enough field of view to be able to image enough sky to discover rare objects.