Pluto hasn't been a planet for almost 20 years. In the early 2000s, scientists discovered several objects of a similar size to Pluto. So, during the summer of 2006, members of the International ...

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 ...

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 ...

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated. (WHNT) — Despite being “demoted” and renamed ...

Claims that the Solar System has a tenth planet are bolstered by the finding by a group led by Bonn astrophysicists that this alleged planet, announced last summer and tentatively named 2003 UB313, is ...

Pluto's largest moon, Charon, likely formed through a capture event in the early, crowded Kuiper Belt. Three-body encounters and tidal forces allowed Charon to lose energy and become permanently bound ...

For the first time, NASA’s Hubble Space Telescope has seen distinctly the “tenth planet,” currently nicknamed “Xena,” and has found that it is only slightly larger than Pluto. Though previous ...

NASA's New Horizons spacecraft captured this high-resolution enhanced color view of Pluto that is inserted beneath the Short Wave logo. The image combines blue, red and infrared images taken by 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 ...