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 ...

Giant, ridge-like structures of methane ice, known as "bladed terrain," may be much more abundant along Pluto's equator than previously realized, a new study suggests.

The only larger dwarf planets in our solar system are Pluto, which has a diameter of 1475 miles, and Eris, which has a diameter of 1445 miles. 2007 OR10 is the third biggest dwarf planet in our ...

A so-called 10th planet discovered last year is bigger than Pluto, scientists say they have confirmed. The astronomers who spotted the icy, rocky body -- known as 2003 UB313 -- had reported only a ...

The spacecraft's flyby of Pluto and its five known moons is providing valuable insight into the solar system's Kuiper Belt, which contains icy objects that range in size from boulders to dwarf ...

Pluto is so far from Earth, and so small, that its size isn't precisely known. When forming their model, the researchers assumed that the diameter of Pluto is roughly 1,429 miles (2,300 kilometers).

Brown previously reported that UB313 was thought to be larger than Pluto and estimated that it was most likely between 1,398 miles and 2,175 miles in diameter.