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 ...

PHOENIX – The Pluto Discovery Telescope at Lowell Observatory has reopened for the first time in a year after undergoing renovations. The telescope in Flagstaff was made famous on Feb. 18, 1930 when ...

The planet Neptune wobbled in its orbit around the Sun. That could only mean one thing, astronomers said: There was a ninth planet out there, somewhere, lurking in the fringes of the solar system.

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 ...

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 ...

An amateur astronomer discovered Pluto 95 years ago today. The former planet will complete an orbit in another 153 years. On February 18, 1930, just two weeks after his 24th birthday, Clyde Tombaugh ...

Pluto was reclassified as a dwarf planet in 2006 when the IAU redefined what it means to be a planet, declaring that a planet must be a celestial body that orbits the sun, is round or nearly round and ...

CAPE CANAVERAL, FL -- Come Tuesday, Clyde Tombaugh will pass within 7,800 miles of the icy world he discovered 85 years ago. His ashes are flying on NASA's New Horizons spacecraft on humanity's first ...

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 ...

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 ...

(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 ...