How many dwarf planets are there in our solar system? The recent discovery of 2017 OF201 makes the tally anywhere between ...

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

Pluto was once considered the ninth planet in the solar system, it was demoted in 2006 to dwarf planet status. We explore this icy body in more detail here.

Named for the shadow-dwelling god of the underworld, the small but mighty planet is associated with sex, death, destruction and much more.

In the time Pluto was found, classified as a planet and reclassified as a dwarf planet, it has not completed one orbit. One year on the distant ice planet is 248 Earth years, and one day is 153 ...

Pluto was long considered our ninth planet, but the International Astronomical Union reclassified Pluto as a dwarf planet in ...

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.

Pluto was demoted from a planet to a dwarf planet in 2006. So why is its status still so controversial today?

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

Because of this, the IAU reclassified Pluto as a dwarf planet, a category that includes other small, round objects in the outer solar system.

A group of planetary scientists argue that the definition of "planet" is outdated and suggest a definition that includes exoplanets.

Come on down to the underworld, folks — we’re talking about Pluto. Named for the maiden-snatching, shadow-dwelling god of the underworld, the small but mighty planet Pluto is associated with ...