[h=1]Evidence grows for giant planet on fringes of Solar System[/h] Gravitational signature hints at massive object that orbits the Sun every 20,000 years.
20 January 2016 A century after observatory founder Percival Lowell speculated that
a ?Planet X? lurks at the fringes of the Solar System, astronomers say that they have the best evidence yet for such a world. They call it Planet Nine.
Orbital calculations suggest that Planet Nine, if it exists, is about ten times the mass of Earth and swings an elliptical path around the Sun once every 10,000?20,000 years. It would never get closer than about 200 times the Earth?Sun distance, or 200 astronomical units (au). That range would put it far beyond Pluto, in the realm of icy bodies known as the Kuiper belt...
