"Believed to be up to ten times the mass of the Earth and with an orbital period of up to 20,000 years, Planet Nine, if it exists, will be situated somewhere beyond the orbit of Neptune." by T.K. Randall via Unexplained-Mysteries Orbital inconsistancies indicative of a mysterious hidden planet in our solar system may have an alternative explanation. Nobody knows exactly where it is, how big it is or if it even exists at all, but when researchers at the California Institute of Technology revealed in 2016 that the existence of a ninth planet in our solar system was a very real possibility, the hunt for this enigmatic new world began in earnest. Believed to be up to ten times the mass of the Earth and with an orbital period of up to 20,000 years, Planet Nine, if it exists, will be situated somewhere beyond the orbit of Neptune. As things stand, however, it is looking increasingly unlikely that it is actually out there at all. Now a new study has cast even further doubt on the possible