These icy bodies orbit the sun just like the major planets, yet they follow their own rules, often traveling along elongated ...

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 ...

The heart's brightness arises from sunlight reflection, while red patches, formed by tholins, showcase Pluto's atmospheric ...

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, once considered the ninth planet, was reclassified as a dwarf planet in 2006 because it shares its orbital path with other objects. Despite its demotion, this distant world continues to ...

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 ...

Astronomers using the Hubble Space Telescope have discovered a fourth moon orbiting Pluto. Pluto - for the record - is still classified as a dwarf planet. Astronomer Larry Wasserman of Lowell ...

NASA's Hubble Space Telescope detected material from a Pluto-like body spiraling into a white dwarf star 260 light-years away from Earth. Credit: NASA / JPL-Caltech / Tim Pyle illustration For 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 ...