Pluto Fire initially started 2:20 p.m. May 24 in Siskiyou County. Since its discovery 15 hours ago, it has burned 12 acres.

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

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

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

With Pluto's "demotion" to dwarf planet status, it’s understandable that the IAU faced criticism from the public for ...

(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?

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 ...

As Pluto passed in front of those far-away stars, their light shining through its atmosphere offered clues as to its status. Using this data, scientists were able to track a dramatic increase in ...

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 ...

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 ...

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.