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's discovery was widely celebrated, especially in the U.S. After all, it was the first planet discovered in the new world, and America needed the win in 1930. "I think because it was discovered ...

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 the ...

FLAGSTAFF, Ariz. (AP) — The observatory where Pluto was discovered is taking full advantage of a flyby of the icy dwarf planet Tuesday with astronomy-themed face painting, an extra Pluto presentation ...

Pluto, discovered 90 years ago on Feb. 18, 1930, was long considered the solar system's ninth planet. Although small, it orbits the sun and has the spherical shape required to be considered a planet.

Earth has a newly-discovered neighbor in the solar system. But the heavenly body – possibly a dwarf planet à la Pluto – isn't a frequent visitor. Located beyond Neptune, its extreme orbit ...

FLAGSTAFF, Ariz. It's been 75 years since the discovery of Pluto, but it remains a mystery. Perhaps in another 10 years some of its secrets will be revealed when a space probe gets close enough for a ...

Clyde Tombaugh noticed a speck of light that was Pluto in 1930. — -- Clyde Tombaugh is finally getting to visit the speck of light he spotted at the edge of the solar system in 1930. New Horizons ...

(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 ...