Published on Nov 11, 2015
Move aside, Sedna and 2012 VP113. There’s a new most distant object in our solar system, and it strengthens the hypothetical case for an unseen large planet at the outer boundaries of our solar system.
The object, V774104, was announced today at the American Astronomical Society’s Division for Planetary Sciences meeting in National Harbor, Maryland. Scott Sheppard of the Carnegie Institute characterized the potential planet as between 300 and 600 miles in diameter, on par with a medium-sized moon. This makes it a likely dwarf planet, as it’s roughly the size of Ceres in the Asteroid Belt.
At 103 astronomical units out (or 103 times the distance of the sun to the Earth), this is the most distant object ever recorded, besting Eris, Sedna, and 2012 VP113. It also adds on to a case built on the discovery of the latter, whose unusual orbit points to the tug of a distant planetary-mass object. Though previous surveys have ruled out anything above the size of Saturn, there still could be a Neptune-sized world or a super-Earth (or even two) farther out, too dark and distant to detect. For now, though, this is just speculation that can’t be ruled out. There’s also the possibility that the objects were tugged into their present orbits by a passing star around the time of the formation of the solar system.