Planet Nine is one of the greatest urban legends of space. Planet Nine is a rogue planet that is ten sizes bigger than the Earth. 5,000 times the mass of Pluto. Its orbit around the sun is estimated by various scientists and researchers to be within a range of 3,600 – 20,000 years. Conspiracy theorists believe that when the orbits of Earth and Planet Nine meet, it’s total destruction for Earth.
Ancient Sumerians were among the first recorded astronomers. Researchers are divided on whether the Sumerians believed in a heliocentric five or twelve planetary solar system. The more popular theory is the Sumerians believed in a twelve planetary system. It included the Sun, Moon, and Pluto before it was demoted to a dwarf planet in August 2006. That leaves a tenth mystery planet somewhere in our outer solar system’s orbit. A Sumerian cylinder seal artifact known as “VA243” is used as evidence to support this theory. Other researchers discount the artifact as a symbolic seal representing the hierarchy of Sumerian deities rather than the solar system.
Around January 2016, Caltech astronomers Konstantin Batygin and Mike Brown publicly hypothesized that there is evidence of a supersize planet based on the odd, elongated orbits of the outer solar system planets. Batygin and Brown named the mystery planet, “Planet Nine.”