This new theory helps explain the large, 1,600-kilometer-wide heart-shaped area on Pluto's surface covered by a thick layer of nitrogen ice, which has intrigued scientists since its discovery by ...

The controversy endures over Pluto's true status, but the solar system underdog continues to capture hearts across the globe. Clyde Tombaugh didn't set out to discover Pluto when he sent his ...

When NASA’s New Horizons mission flew past Pluto in 2015, it gave humanity our first glimpse of a colossal depression on the isolated world. It's named Sputnik Planitia. Comparable in size to ...

Pluto, with its heart-shaped glacier, as captured by the New Horizons spacecraftJPL/NASA Pluto will mark a birthday of sorts on March 23, 2178. No one is likely to be there to celebrate it ...

(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?

According to the IAU, a planet must: Orbit the sun (Pluto does this). Be spherical in shape (Pluto is round due to its gravity). Clear its orbit of other debris (Pluto fails this). Pluto shares ...

Pluto will mark a birthday of sorts on March 23, 2178. No one is likely to be there to celebrate it, of course. Even if humanity is a multi-planet species by then, it would be a decided challenge to ...

open image in gallery Pluto was once our solar system's ninth ... The three categories are distinct in their color and shape. Notably, they are generated by molecules that contain water and ...

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 ...