Over the past decade, researchers have been puzzling through Pluto’s mysteries. Meanwhile, the New Horizons probe heads for interstellar space.

It took over nine years for New Horizons to reach Pluto after blasting off atop an Atlas 5 rocket on Jan. 19, 2006. After ...

The James Webb Space Telescope (JWST), operated by NASA, has uncovered intriguing new details about Charon—Pluto’s largest moon—including the presence of ...

More like Pluto, in some ways, than Pluto is like the other planets. Finding all these new objects, it became necessary for astronomers to get more specific about what we mean by the word "planet ...

After all, it's not like anyone had truly seen Pluto before New Horizons performed its 2015 fly-by. And sure enough, afterward, there was definitely a shift — in Pluto's favor.

Though Pluto has formally been considered a dwarf planet for almost two decades, it still has many lessons left for planetary scientists — including hints about how the solar system formed.

Arizona Gov. Katie Hobbs signed a bill making Pluto the official state planet. It was discovered at an observatory in Arizona, but was downgraded to a dwarf planet in 2006.

Pluto, therefore, is not the gravitationally dominant object in its neighborhood — and thus, not a planet, according to the new definition. Sign up for the Live Science daily newsletter now ...

In fact, since Pluto’s demotion, we’ve learned that Pluto is even more like the other planets than we thought back when it was formally considered a planet!

The official definition of a “planet” could be set to change again soon. Last time that happened, Pluto was kicked out of the club, but the new proposed definition is designed to be more ...

It was one of the most ambitious missions for NASA since the turn of the century, with photos reshaping what scientists know ...