Perhaps because they still feel bad about taking away Pluto's official planet privileges in 2006, scientists using the Hubble Telescope discovered a fifth moon orbiting the former 9th planet. The moon, creatively titled S/2012 (134340) 1, or P5, is irregular in shape and roughly 6-15 miles across.

Astronomers say the Earth has two moons at this very moment. Crazy astronomers must have forgotten their glasses at the lab.

Scientists have long puzzled over the odd shape of the Moon: One side is "dominated by low-lying lava plains" while the other is "composed of highlands." But we may finally know why! Because the moon is a murderer.

Astronomers using Hubble Space Telescope have discovered a new, 21 mile-wide moon orbiting Pluto. They're going to call it "P4" until they can come up with a better name for it.