Why was Pluto reclassified as a dwarf planet? One might think that it’s purely a matter of size. Mercury, the smallest of the ...

Previously, scientists thought Pluto was the only planet-sized KBO, so they had no reason to challenge its status. However, ...

The relative quantities of volatile gases like methane and ethane can reveal key details about distant Kuiper Belt objects.

But Charon was half the size of Pluto itself, so big that the Pluto-Charon combination are sometimes referred to as a double planet, according to NASA. In August 2006 the International ...

Although Seeing in the Dark doesn't directly discuss Pluto, it does celebrate the joy of observing planets. Viewers who watch the show may wonder what happened to Pluto in 2006 and whether any of ...

A blue atmosphere, smooth areas, and youthful mountain ranges - this dwarf planet is full of surprises. When NASA's New Horizons probe flew past Pluto in July 2015, the images it returned astonished ...

A surprising chemical difference between Pluto and Sedna, another dwarf planet in the distant Kuiper ... "Since Gonggong is similar in size to Sedna, we believe methane must have escaped from ...