In a universe full of planets, 2007 OR10 is something special. It’s big, just slightly smaller than the size of Pluto. And it’s close, within our very own solar system. So how did it still manage to ...

Later, it was reclassified as a dwarf planet, yet its mysterious charm has not diminished at all. Why is that? Because Pluto's complex and elusive terrain is like a mysterious key that may hold the ...

This composite image shows color views of Pluto (right) and its largest moon Charon as they appeared on July 11, 2015 to NASA's New Horizons spacecraft ahead of a historic flyby on July 14.

Pluto has long been one of the most debated celestial bodies in our solar system. Once classified as the ninth planet, it was ...

"Makemake is one of the largest and brightest icy worlds beyond Neptune, and its surface is dominated by frozen methane," ...

Pluto has just been found to be ever so slightly bigger than we thought, having a diameter of 2,370km. The measurement was made by the New Horizons probe which is just about to flyby the dwarf world.

“Pluto is showing us a diversity of landforms and complexity of processes that rival anything we’ve seen in the solar system,” said New Horizons Principal Investigator Alan Stern, of the Southwest ...

Pluto's surface hosts blades of ice that soar to the height of skyscrapers — and researchers have narrowed down exactly how the dramatic features form. According to new research, the blades are made ...

As elementary schoolers, we learned the order of the planets. Maybe your teacher even had a snappy mnemonic like “My Very Educated Mother Just Served Us Nine Pizzas” or “My Very Educated Mother Just ...

NASA's New Horizons mission has answered one of the most basic questions about Pluto -- its size. Mission scientists have found Pluto to be 1,473 miles (2,370 kilometers) in diameter, somewhat larger ...