The confirmed discovery of 2015 TG387, aka ‘The Goblin’ (it was monitored around the Halloween period here on Earth) was thanks to the largest and deepest survey ever conducted on distant solar objects, in the hunt for the ever-elusive 'Planet 9,' that has been carried out by a team from the Carnegie Institution of Washington, Northern Arizona University, and the University of Hawaii.
The 300 km-wide ‘Goblin' was discovered roughly 80 astronomical units (AU) –the average distance between the Earth and the Sun– from our Sun. It takes this planetoid 40,000 years to loop around the Sun once and it’s one of the most inhospitable places ever discovered by humans.
The Goblin has an extremely elongated orbit, which appears to be under the gravitational influence of a giant object that could be the obscure Planet 9 (also known as Planet X).
“These distant objects are like breadcrumbs leading us to Planet X. The more of them we can find, the better we can understand the outer Solar System and the possible planet that we think is shaping their orbits—a discovery that would redefine our knowledge of the Solar System’s evolution,” one of the researchers, Scott Sheppard, explained.
The team had to wait a long time to ascertain the Goblin planet's orbit as it moves so slowly. It was originally spotted by the Japanese Subaru 8-meter telescope located atop Mauna Kea in Hawaii in 2015. Further sightings by observatories in Arizona and Chile between 2015 and 2018 have confirmed its existence.
The Goblin is one of three objects clustered together in a mysterious region of the Universe known as the Oort cloud, an area beyond Pluto that was once thought largely barren and bereft of celestial activity. The three objects' proximity to one another has been taken as yet more evidence that a giant planet, with a massive gravitational pull, is shepherding objects at the outer limits of our Solar System.
The next run of observations begins in November, when the team may finally spot the enigmatic Planet 9, if it even exists.
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