Pluto and the more distant dwarf planets fail to meet this criterion. If Pluto were to keep its planetary status, those dwarf planets would also need to be classified planets. While astronomers ...

Once the quirky underdog of our solar system, Pluto held planetary status until 2006, when it got a cosmic demotion that still stings space fans. Discovered in 1930, Pluto was the ninth planet for ...

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

Pluto has never been much of a planet — small, wired orbit, not much atmosphere — and questions about its status have been raised periodically since its discovery 76 years ago. This week ...

It’s a sloppy definition,” he says. His stance is that the one sticking point for those who wanted to strip Pluto of its planetary status — the “clear” orbit requirement — isn’t ...

Astronomers find evidence of a possible ninth planet beyond Neptune, reigniting the debate about the formation of the Solar ...

Learn about the recently discovered trans-Neptunian object that may eventually join Pluto as a dwarf planet, found at the ...

The first observations of Pluto by NASA’s James Webb Space Telescope (JWST) reveal dramatic phenomena on its surface, like ...

It's an evocative idea that has long bedeviled scientists: a huge and mysterious planet is lurking in the darkness at the ...

Astronomers have announced the discovery of a new dwarf planet in our solar system, named 2017 OF201. Located far beyond ...