Pluto was once called the ninth planet, but in 2006, scientists changed its status to a dwarf planet. A planet must clear its orbit of other objects, but Pluto shares its space with many small icy ...

For one reason or another, some people are still upset about Pluto's demotion from planet to dwarf planet. This demotion, by the way, occurred all the way back in 2006. So, what does famed ...

"Pluto was found really close to where Lowell thought a planet should be ... you have this third zone of icy dwarf planets, ...

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

For decades, it has consisted of nine planets, even as scientists debated whether Pluto really belonged ... as “2003 UB313” become the 10th planet? Should Pluto be demoted?

An curved arrow pointing right. NASA's New Horizons spacecraft took us to Pluto for the first time in July 2015. Scientists are astonished by the incredible features they've observed on the dwarf ...

Pluto is too far away from Earth to be seen with the naked eye. If you stood on Pluto's surface, the Sun would merely appear to be a very bright ... about the dwarf planet and its orbiting moon.