Science

Astronomers discover distant planet billions of miles beyond Pluto

Astronomers discover distant planet billions of miles beyond Pluto

Saturn can be seen at 10 AU and Earth is, of course, at 1 AU, as the measurement is defined as the distance between the Sun and our home planet.

But, boasting a larger orbital semi-major axis, 2015 TG387 has the ability to travel farther away from the Sun, reaching a whopping 2,300 AU at its most extreme point.

Prior to finding the Goblin, Sheppard and Trujillo had already found 2012 VP113 - the most-distant object to date. Scientists have found mathematical evidence of a still-undiscovered planet at the edge of the Solar System and it explains the unique orbit of the objects in the Kuiper Belt.

"I think we are nearing the 90 percent likelihood of Planet X being real with this discovery", said Scott Sheppard, an astronomer at the Carnegie Institution for Science. "We are only seeing the tip of the ice berg", Sheppard said in an email.

2012 VP113 has the most distant orbit at perihelion, at just over 80 AUs.

"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", said Sheppard.




"Objects such as 2015 TG387 allow us to probe not only the makeup of the solar system itself but also the gravitational mechanisms that sculpt it", said Konstantin Batygin, a planetary scientist at the California Institute of Technology who was not involved with the observation. Goblin's orbit is extremely elongated - so stretched out that it takes 40,000 years for it to circle the sun.

Like the other objects found by Sheppard and his team on the edge of the solar system, the Goblin behaves in a way that is pushed into a similar orbit by some unseen force. According to the paper, " 2015 TG387 continues the longitude clustering trend seen for the inner Oort cloud objects and ETNOs, which might be caused by a massive planet (Planet 9) shepherding these objects". Its large orbit and slow movement allowed Sheppard and his team to study it for several years so they could properly understand it. Astronomers first observed the dwarf planet on October 13, 2015, from the Subaru telescope at Hawaii's Mauna Kea Observatories.

With a diameter of just 186 miles, The Goblin is also on the small side, even for a dwarf planet. So it may come as a surprise to some that there is a potential new contender for the ninth planet, based on the discovery of another newly discovered celestial body with an amusing nickname. "We believe there are thousands of dwarf planets in the distant solar system".

Sheppard and his colleagues continue their survey, the largest and deepest ever for distant solar system objects, by observing the northern and southern skies at all times of year.

In case of Planet Nine/X, bias comes in the form of observing bodies with an unusual orbit that stand out precisely because they have anomalous orbits while the ones with normal orbits haven't been spotted yet. And it never gets closer to the sun than 6 billion miles, about twice as far as Pluto is from the sun.

Some have previously theorized the existence of a planet that is larger than Earth, situated at the brink our solar system and able to influence the way in which these smaller worlds shape their orbit.