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:NASA asteroid tracker: LOOK OUT as 130FT asteroid skims Earth this weekNASA 'Big Freeze' BOMBSHELL: How space agency predicts END to life on EarthScientists solve mystery of ‘VIRGIN’ birth: UK scientists STAGGERED by 'fish called Mary'White House Panel Will Study Whether Climate Change Is a National Security Threat. It Includes a Climate Denialist.Solar storm set to hit Earth TOMORROW after HOLE opens up in the SunSupermoon 2019: When is the next Supermoon this year? THIRD celestial event of the year