What was discovered in Flagstaff, Arizona, and killed off in Prague? If you answered "Pluto's planethood," your grasp of the astronomical is excellent. Feb. 18 marks the 95th anniversary of the ...

Pluto will complete its first orbit since 1930 in 2178, a historic 248-year space journey that spans generations of humans.

Once the quirky underdog of our solar system, Pluto held planetary status until 2006, when it got a cosmic demotion that still stings space fans. Discovered in 1930, Pluto was the ninth planet for ...

Pluto has long been one of the most debated celestial bodies in our solar system. Once classified as the ninth planet, it was redefined in 2006 as a dwarf planet, a decision that still sparks ...

Pluto, with its heart-shaped glacier, as captured by the New Horizons spacecraft Pluto, with its heart-shaped glacier, as captured by the New Horizons spacecraftJPL/NASA Editor at Large Pluto will ...

Finally, a family portrait of Pluto is beginning to emerge! For the first time ever, astronomers have captured two never-before-photographed moons orbiting Pluto. NASA's New Horizons spacecraft ...

WASHINGTON, Sept 26 (Reuters) - Astronomers using the Hubble Space Telescope have observed a white dwarf - a highly compact stellar ember - that appears to have gobbled up an icy world akin to the ...

(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? If ...