Pluto

The team behind the New Horizons mission to Pluto recently pulled of a challenging observation of the spacecraft's next target, MU69, as the object eclipsed a distant star.

If you could go anywhere in the Solar System, where would it be?

Fusion-powered rockets that are only the size of a few refrigerators could one day help propel spacecraft at high speeds to nearby planets or even other stars, a NASA-funded spaceflight company says.

New Horizons team members have traveled to Argentina and South Africa to watch the Kuiper Belt object 2014 MU69 — the mission's next flyby target — pass in front of a distant star.

The dwarf planet 2007 OR10, informally known as "Snow White," has a moon that's between 150 miles and 250 miles (240 to 400 kilometers) wide, a new study reveals.

Some scientists believe Pluto's red "whale"-shaped region is the mark of a giant impact — the same one that produced Pluto's huge moon Charon.

The first up-close look at Pluto was so intriguing that some researchers want to go back and spend a lot more time studying the icy world.

I don't know about you, but I was shocked when NASA's New Horizons mission sent back its first batch of high-resolution images of the surface of Pluto.

Recent observations that a tiny object in our solar system is a likely dwarf planet has some planetary scientists grumbling again about Pluto's demotion to that status.

New observations reveal that the far-flung object 2014 UZ224 (informally known as DeeDee, for "Distant Dwarf") is about 395 miles (635 kilometers) wide — big enough to claim "dwarf planet" status.

New Horizons, which performed the first-ever flyby of Pluto on July 14, 2015, entered hibernation Monday afternoon (April 10) for the first time in nearly 2.5 years, mission team members said.

NASA's New Horizons spacecraft is now more than halfway from Pluto, which it famously flew past in July 2015, to its next flyby target: a distant object known as 2014 MU69.

Citizen scientists have flagged four objects for follow-up study in the hunt for the hypothetical Planet Nine.

After more than a decade of controversy, the debate over the icy world's demotion to "dwarf planet" status shows no sign of stopping

A group of planetary scientists is making the case for a new definition of a planet; this one would include Pluto and most moons. Here's why these researchers think the new definition is better.

Pluto's status as a "dwarf planet" is once again stirring debate. This comes as some planetary scientists are trying to have Pluto reclassified as a planet – a wish that's not likely to come true.

Pluto's famous heart-shaped feature is on the road to getting an official name, nearly two years after its discovery.