At a press conference, New Horizons' top dog Alan Stern just announced that his team has calculated Pluto's most accurate diameter yet: about 1,473 miles from one end to the other, give or take 12 ...

NASA's New Horizons mission has answered one of the most basic questions about Pluto—how big is it? Mission scientists have found Pluto to be 1,473 miles in diameter, somewhat larger than many prior ...

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 ...

Explore Pluto's reclassification as a dwarf planet and how Eris's size advantage challenges old beliefs about planetary status. Images taken in December 2005 by Brown and others with the Hubble Space ...

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.

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 ...

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 ...

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) may have detected the dusty hallmarks of an entire family of Pluto-size objects swarming around an adolescent version of our ...