Pluto

Pluto's heart-shaped feature, which NASA's New Horizons spacecraft discovered during its epic July 2015 flyby of Pluto, drives atmospheric circulation on the dwarf planet, a new study suggests.

Pluto lost its "official" planet status over a decade ago, but fans of the solar system's underdog are still rooting for it. And NASA Administrator Jim Bridenstine is one of them.

The battle scars on Pluto may reveal secrets about the formation of the early solar system.

The final photos that NASA's New Horizons spacecraft snapped of Ultima Thule during the probe's epic Jan. 1 flyby reveal the distant object to be much flatter than scientists had thought.

Sing along if you know the words: When the moon hits your eye, like a big pizza pie, that's a planet!

The long-simmering argument about Pluto's planethood has just flared up again.

On the two-year anniversary of the New Horizons probe's flyby of Pluto, mission scientists unveiled two detailed global maps of the dwarf planet and its largest moon, Charon.

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.

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.

Nearly two years after its historic encounter with the dwarf planet Pluto, NASA's New Horizons spacecraft is getting ready for its next big adventure in the icy outskirts of the solar system.