They found an unusual match: a massive planet in an anti-aligned orbit, which is an orbit in which the planet’s closest approach to the sun is 180 degrees across from the closest approach of the objects and known planets in the solar system. If you knew where to look, this planet-sized object would be visible through a suitable telescope. Astronomers think the huge, distant planet is likely gaseous, similar to Uranus and Neptune. “By “giant” we mean the size of Neptune, and when we say “outer solar system” we mean 10 to 20 times farther away than Pluto”.
Computer simulations show that the mystery planet, if it exists, would orbit about 20 times farther away from the sun than Earth, said astronomers with the California Institute of Technology in Pasadena.
In an interview Brown, a professor of planetary astronomy, also said that “this would be a real ninth planet”.
Brown said the planet has 5,000 times the mass of Pluto and is so big there should be no debate about whether it is a true planet. Pluto, discovered in 1930, was once the 9th planet but is now considered a dwarf planet in the Kuiper Belt.
Perhaps Planet Nine represented a fifth core, that may have gotten too close to Jupiter or Saturn and been ejected into its current, distant orbit, said Brown. It appeared that something with significant gravitational force was slightly “nudging” these objects throughout their trip around the sun.
Unlike the class of smaller objects now known as dwarf planets, Planet Nine gravitationally dominates its neighborhood of the solar system – one of the key tests for planet classification. And they drew the attention of Brown and Batygin. What should we name the new planet, assuming no one likes the ring of Planet X?
A ninth planet has always been hypothesised – and become the basis of some conspiracy theories – originally going under the name Planet X. It was first talked about more than a century ago, and looking for that planet was what brought astronomers to find Pluto. It could also provide an explanation for the mysterious orbits that two of them trace.
In a paper published in the latest issue of The Astronomical Journal, the duo detail how they came to find the planet when a student of Brown’s noticed that 13 large objects in the Kuiper Belt were behaving oddly, as though they were being influenced by a much larger body. At first, a planet in this type of orbit seemed unlikely.
“Your natural response is ‘This orbital geometry can’t be right”.
“There is no planet found. It’s all circumstantial evidence”, Sheppard said. Alas, no one has actually seen Planet Nine at this point in time.
They’ve nicknamed the new object Planet Nine. Brown and Batygin are only making an educated guess based on their knowledge of how planets interact with each other.