Clyde Tombaugh discovered Pluto in 1930 at Lowell Observatory in Flagstaff. Here's how Pluto won - and lost - its planetary ...

Pluto was identified in 1930, but by 1994, it was still little more than a blurry pixelated smudge on astronomers’ screens. Today, we marvel at its icy plains, towering mountains, and stunningly ...

In July, NASA's New Horizons spacecraft took us to Pluto for the first time. The photos the craft sent back so far have astounded researchers. New Horizons principal investigator Alan Stern says ...

(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 was discovered at Lowell Observatory in Flagstaff, Arizona in 1930 and was considered our ninth planet until 2006. The International Astronomical Union reclassified Pluto as a dwarf planet ...