One Pluto year equals 248 Earth years. At 1473 miles in diameter—about half the width of the United States—Pluto is the ...

Elon Musk, under the username "Kekius Maximus," has joined William Shatner in advocating for Pluto's reclassification as a planet. Shatner playfully suggested Musk persuade the President via executive ...

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 ...

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

song, Interplanet Janet. Upon the discovery of its existence in 1930, Pluto enjoyed decades of special status as one of the solar system's planets. Then, in the summer of 2006, Pluto was demoted.

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

This sparked debate about Pluto's status in the planetary canon, which came to a head at a 2006 meeting in Prague. That year, the IAU tasked a small committee with creating a working definition of ...

There’s a new frozen oddball orbiting the Sun, and it’s not your average space rock. It’s a planet—a minor one, to be ...

Despite the change, Pluto remains a beloved celestial body, and some astronomers still debate whether it should regain its planetary status. Yes. Clyde Tombaugh discovered Pluto on Feb. 18 ...

(Correction: An earlier version of this story misstated how far Pluto is from the sun. The correct number is 3.7 billion miles.) What was discovered in Flagstaff, Arizona, and killed off in Prague?