The debate over Pluto’s planetary status has been ongoing since its reclassification as a “dwarf planet” in 2006 by the ...

With a diameter of 1,440 miles, Pluto is farthest from the sun. While major planets make roughly circular orbits, Pluto ...

On Aug. 24, 2006, the International Astronomical Union (IAU) decided that Pluto wasn't a planet anymore. Instead, Pluto is now officially classified as a dwarf planet along with four other confirmed ...

On August 24, 2006, Pluto ceased to be considered a planet. A mixture of rock and ice located in the Kuiper Belt, a region of icy objects beyond the orbit of Neptune. This demotion ...

Planet X or not, Pluto existed. Smaller than the Moon, but inhabiting the realm of the giant planets, it defied our notions regarding the architecture of the Solar System.

Today in the history of astronomy, our solar system's ninth member is downgraded to a dwarf planet.

Sure, Pluto received a bit of a demotion when its status as a planet was called into question a few years ago, but that doesn’t mean it stopped giving scientists reasons to study it. And thanks ...

Planet X or not, Pluto existed. Smaller than the Moon, but inhabiting the realm of the giant planets, it defied our notions regarding the architecture of the Solar System.

On January 17, 2006 the New Horizons mission will launch for Pluto, the last unexplored planet of the solar system — or is it? Some scientists now claim that Pluto does not deserve its planetary ...

A group of planetary scientists argue that the definition of "planet" is outdated and suggest a definition that includes exoplanets.

The International Astronomical Union in Prague ruled today that the much-maligned Pluto no longer qualifies as a planet under historic new guidelines, thereby stripping Pluto of the planetary ...