Planet Nine discovery: What is Planet 9? Is Planet X in our solar system? PLANET Nine, aka Planet X, has perplexed astronomers since it was first proposed in 2014. So what exactly is Planet X and is Planet 9 in our solar system? Share: Facebook Twitter Google+ Stumble Digg Email ThisBlogThis!Share to XShare to Facebook Related Posts:Antarctica MYSTERY: How scientists uncovered bizarre ‘DEATH STAR' fish with 50 LIMBSNASA Moon landing: NASA chief chief vows ‘We will go to the Moon’ with £16billion budgetSolar storm INCOMING: Massive blast of cosmic rays from the Sun heading to Earth on FRIDAYNASA asteroid tracker: A 390FT asteroid will skim Earth THIS WEEKEND at 16,800MPHDinosaur BOMBSHELL: New theory reveals ferocious T-rex was actually 'FLUFFY'F.D.A. Moves to Restrict Flavored E-Cigarette Sales to Teenagers