So things stood for 65 years. Although Pluto's orbit was more elongated than the other planets' (and even crossed the orbit of Neptune—not the kind of thing you would expect a decent planet to ...

Everyone's favorite dwarf planet, Pluto, was discovered just 95 years ago. Here's the story of how the once-ninth planet was ...

(See what scientists say about Pluto’s status as a planet.) As early as the 1840s, a tricky calculus foretold the existence of a planet beyond the orbit of Neptune. Calculations based on Neptune ...

Officially named 2000 EB173, the object is a ball of rock and ice measuring 373 miles (597 km) in diameter -- about one-fourth the size of the planet Pluto. The object is classified as a minor ...

SEE ALSO: 4 rad dwarf planets that aren't Pluto "The icy worlds beyond Neptune trace how the giant ... 2015 RR245's orbit (in yellow) with other dwarf planets for context. Credit: Alex Parker ...

and as Neptune moved into its present orbit, its gravity tugged the remaining smaller bits with it deeper into space. Some of the pieces combined to form larger bodies like Pluto, but something ...

Carrying enough fuel to slow it into a Pluto-centric orbit would have added lots of ... an asteroid belt beyond Neptune. New Horizons won’t make it to any of the other Kuiper dwarves, but ...

(For example, Neptune hasn't purged its orbit of large bodies—including Pluto, which crosses Neptune's path.) "It's a sloppy definition," says Alan Stern of the Southwest Research Institute in ...

It takes Pluto slightly over 248 Earth years to orbit the sun, which means that ... astronomers had observed in the orbits of Uranus and Neptune. He searched for Planet X from 1905 until his ...

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

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 ...

The Kuiper Belt is a region in space beyond the orbit of Neptune that's home to Pluto and most of the known dwarf planets, as well as some comets that are thought to be relics of the solar system ...