The Solar System could end up with nine planets once more, but astronomers are yet to spot the ninth one. This mysterious body, should it exist, is estimated to be far outside the solar system as we know it, and scientists have uncovered fresh evidence to support its existence.
"Planet Nine" should exist, say astronomers because of another object outside the Solar System called the 2015 BP 519. This unimaginatively named body is classified as an Extreme Trans-Neptunian Object (ETNO) because of its size and distance from the Sun, reports Futurism.
Astronomers have been watching this other object, BP 519, quite closely since 2014. The team spent about 1,110 days tracking its progress and orbit as part of the Dark Energy Survey Collaboration, using a Dark Energy Camera from an observatory in Chile.
Another reason that made this ETNO interesting was owing to the nature of its orbit around the Sun.
BP 519 reportedly travels about 450 times the distance between the Sun and Earth, in an orbit that is a lot more inclined than the rest of the Solar System's planets - it is nearly perpendicular, notes the report. All other planets have a more or less similar plane of orbit around the Sun.
As to what BP 519's orbit has to do with the existence of Planet Nine, astronomers theorise that there needs to be something large and dense enough to exert gravity strong enough to pull the ETNO this far out of line. This means there has to a planet out there, four times the size of Earth, and ten times as dense.
Without this possible planet out there, researchers could not account for the strange behaviour of BP 519. The report further states that the orbit of this planet, should it exist, will be about 10 to 20 thousand Earth years.
Having said that, this also does not mean that there definitely is, without any doubt, a planet with the mentioned specs out there. Scientists are yet to spot it, despite the New Horizons and two Voyagers that have already left the Solar System, and have not encountered or even spotted the theorised planet so far.
This speculated planet is called Planet Nine simply because Pluto is not a planet anymore. Apologies to the Pluto fans out there.