New evidence is emerging that our solar system may be home to a planet – dubbed Planet X – that has yet to be seen by even the most powerful telescopes. This is not some small speck of a planet, but one that may be the size of Neptune. Scientists theorize Planet X may take 15,000 years to orbit the Sun; by comparison Neptune’s orbit takes 165 years. If true, the discovery of Planet X will explode our current understanding of the solar system. See this fascinating video to learn more.