npr:

The astronomer whose work helped kick Pluto out of the pantheon of planets says he has good reason to believe there’s an undiscovered planet bigger than Earth lurking in the distant reaches of our solar system.

That’s quite a claim, because Mike Brown of Caltech is no stranger to this part of our cosmic neighborhood. After all, he discovered Eris, an icy world more massive than Pluto that proved our old friend wasn’t special enough to be considered a full-fledged planet. He also introduced the world to Sedna, a first-of-its-kind dwarf planet that’s so far out there, its region of space was long thought to be an empty no man’s land.

Now Brown has teamed up with Caltech colleague Konstantin Batygin to do a new analysis of oddities in the orbits of small, icy bodies out beyond Neptune. In their report published Wednesday in The Astronomical Journal, the researchers say it looks like the orbits are all being affected by the presence of an unseen planet that’s about 10 times more massive than Earth (though still much smaller than Uranus or Neptune) — the size astronomers refer to as a super-Earth.

Scientists Find Hints Of A Giant, Hidden Planet In Our Solar System

Image: The imagined view from Planet Nine back toward the sun. Astronomers think the huge, distant planet is likely gaseous, similar to Uranus and Neptune.