For the better part of a century, we believed there were nine planets in our solar system, with Pluto being the farthest from the sun. Since the discovery of more Pluto-sized dwarf planets, that ...

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

Experts postulated a new theory about the largest moon of the dwarf planet Pluto. The planet had five moons among which Charon was the largest and had a diameter of about 754 miles, just over half ...

The ringed gas giant Saturn has officially replaced Jupiter as the planet in our solar system with the most moons. The ...

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

Clyde Tombaugh discovered Pluto in 1930 at Lowell Observatory in Flagstaff. Here's how Pluto won - and lost - its planetary status.

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 ...

In many ways it more nearly resembled Triton, a moon of ... such as Pluto and Eris—the International Astronomical Union in 2006 recommended that they be called "dwarf planets"—much as ...

Many planets have moons, and some planets have many moons - Saturn has more than 50. The Earth has just one moon - the Moon. Pluto is a dwarf planet. As the name suggests, a dwarf planet is ...