Astronomers argue that there’s an undiscovered giant planet far beyond the orbit of Neptune. A newly discovered rocky body has added evidence to the circumstantial case for it.

In early 2016, two planetary scientists declared that a ghost planet is hiding in the depths of the solar system, well beyond the orbit of Pluto. Their claim, which they made based on the curious orbits of distant icy worlds, quickly sparked a race to find this so-called Planet Nine — a planet that is estimated to be about 10 times the mass of Earth. “It has a real magnetism to it,” said Gregory Laughlin, an astronomer at Yale University. “I mean, finding a 10-Earth-mass planet in our own solar system would be a discovery of unrivaled scientific magnitude.”

Now, astronomers are reporting that they have spotted another distant world — perhaps as large as a dwarf planet — whose orbit is so odd that it is likely to have been shepherded by Planet Nine. The object confirms a specific prediction made by Konstantin Batygin and Michael Brown, the astronomers at the California Institute of Technology who first argued for Planet Nine’s existence. “It’s not proof that Planet Nine exists,” said David Gerdes, an astronomer at the University of Michigan and a co-author on the new paper. “But I would say the presence of an object like this in our solar system bolsters the case for Planet Nine.”