Pluto may have lost its status as a full-fledged planet in 2006, but that doesn't mean it's a joke of a world this April Fools' Day and the folks behind Pluto TV want to make that clear.

Pluto, humanity's favorite dwarf planet, is getting some high-profile allies. "Star Trek" actor William Shatner wants to use ...

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

On July 11, 2012, a fifth moon, Styx, was discovered (with an estimated width of 6 miles or 10 km), further fueling the debate about Pluto's status as a planet. The leading hypothesis for the ...

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

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 ...

It’s been 18 years since Pluto’s celestial status was called into question—yet the matter seems far from settled. We asked experts from both sides to make their case. This 2015 NASA image of ...

(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?

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 ...