First: the context – “Astronomers using the Hubble Space Telescope discovered a fourth moon orbiting the icy dwarf planet Pluto. The tiny, new satellite – temporarily designated P4 — was uncovered in a Hubble survey searching for rings around the dwarf planet.”

Next: the funny: (although note that technically, number of moons don’t actually have anything to do with “planet” designation)

Via Defective Yeti.