(Correction: An earlier version of this story misstated how far Pluto is from the sun. The correct number is 3.7 billion miles.) What was discovered in Flagstaff, Arizona, and killed off in Prague?

Pluto, with its heart-shaped glacier, as captured by the New Horizons spacecraftJPL/NASA Pluto will mark a birthday of sorts on March 23, 2178. No one is likely to be there to celebrate it, of ...

Since its discovery in 1978, Pluto's largest moon ... and organic materials responsible for its gray and red coloration." ...

Pluto was discovered 95 years ago on Feb. 18, and even though it was demoted nearly two decades ago, it remains a fascinating part of our solar system. "Pluto is a complex and mysterious world ...