The hypothetical, massive outer Solar System body Planet X is still proving elusive, but the hunt for it has yielded up a different find: a tiny dwarf planet, roughly 2.5 times Pluto's distance at the time it was found.
It's called 2015 TG387 and nicknamed "the Goblin". Also, it's pretty small even for a dwarf planet - barely 300 kilometres (186 miles) across.
But we're pretty excited, because the Goblin is on an extraordinary orbit. According to the researchers, this still suggests that Planet X is somewhere out there, in the cold and dark.
It was found by astronomers Scott Sheppard of the Carnegie Institution for Science, and his colleagues Chad Trujillo of Northern Arizona University and David Tholen of the University of Hawaii. Together, this team is leading the search for Planet X.
