Clyde Tombaugh didn't set out to discover Pluto when he sent his sketches of the night sky to Lowell Observatory in Flagstaff, Arizona in 1929. More than anything, he just wanted to get off the ...

The controversy endures over Pluto's true status, but the solar system underdog continues to capture hearts across the globe. Clyde Tombaugh didn't set out to discover Pluto when he sent his ...

(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, discovered in 1930, was once considered the ninth planet in our solar system. In 2006, the International Astronomical Union reclassified Pluto as a dwarf planet because it doesn't meet all ...