Pluto

There may be a lot more potentially habitable worlds zooming through the cold depths of deep space than scientists had thought.

Hydrocarbon particles in Pluto's atmosphere are responsible for the dwarf planet's surprisingly low temperatures, a new study suggests.

A grassroots movement seeks to build momentum for a second NASA mission to the outer solar system, a generation after a similar effort helped give rise to the first one.

Pluto's surface hosts blades of ice that soar to the height of skyscrapers — and researchers have narrowed down exactly how the dramatic features form.

NASA's New Horizons spacecraft may double its pleasure during its next deep-space flyby 16 months from now.

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.

The frigid, faraway body that NASA's New Horizons spacecraft will zoom by 18 months from now may actually be a cluster of small objects, new observations suggest.

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.

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.