Blurry Hubble imageshave revealed both extremely dark and extremely bright patches on Pluto, and some scientists suspect that smears of organic compounds are painting parts of the dwarf planet dark.

When Pluto and Charon hit ... The theory goes that a Mars-sized planet whacked a primitive version of Earth like a paint ball, casting off a mixture of planetary guts. Rather than forming a ...

For one reason or another, some people are still upset about Pluto's demotion from planet to dwarf planet. This demotion, by the way, occurred all the way back in 2006. So, what does famed ...