It's been about 11 years since Pluto was demoted to dwarf planet status, leaving a 2370km-sized void in our hearts. Since then, the hunt for Planet X -- aptly renamed Planet 9 -- has grown into an international movement to find such an object in the Kuiper Belt beyond Neptune's orbit. Now, scientists Kat Volk and Renu Malhotra from the University of Arizona's Lunar and Planetary Laboratory are upping the ante -- they suggest that a completely different, tenth planetary-mass object is hiding somewhere in the Kuiper Belt as well. Is someone keeping track of all these goddamn hypothetical planets?