|This article is about the recently dicovery of a proposed object. You may be looking for Tyche.|
Planet Nine is a hypothetical large planet in the far outer Solar System, whose presence would explain the unusual orbital configuration of a group of trans-Neptunian objects (TNOs) that orbit mostly beyond the Kuiper belt.
On 20 January 2016, researchers Konstantin Batygin and Michael E. Brown at Caltech announced calculation-based evidence of a massive ninth planet in the Solar System. The predicted planet would be a super-Earth, with an estimated mass of about 10 times that of Earth (approximately 5,000 times the mass of Pluto), a diameter two to four times that of Earth, and a highly elliptical orbit that is so far away that it could take around 15,000 years to orbit the Sun.
On the basis of models of planet formation that might include planetary migration from the inner Solar System, such as the fifth giant planet hypothesis, the authors suggest that it may be a primordial giant planet core that was ejected from its original orbit during the nebular epoch of the Solar System's evolution.
- People were very skeptical about Planet Nine, but are hoping it may be discovered.