Far beyond the orbit of Neptune, in the cold outer reaches of the solar system, circles one of the most consequential small ...

In a groundbreaking discovery, astronomers have identified a potential dwarf planet candidate, 2017 OF201, buried within ...

The reclassification of Pluto as a dwarf planet continues to stir up a hornet's nest of controversy and debate, as Space.com ...

Unpopular opinion time, Pluto being reclassified as a dwarf planet was a great thing for our understanding of the solar ...

A 24-year-old observatory assistant from the Midwest discovered Pluto. Clyde Tombaugh, born in 1906 in Streator, Illinois, ...

Earth was long thought to be the only planet in our solar system with an ocean, but it is beginning to look as though there are underground oceans inside even the most surprising icy bodies. In fact, ...

The discovery of the Kuiper Belt revealed thousands of icy objects near Pluto, challenging its status as a planet. After the ...

Pluto lost its planethood for a very specific reason. Whether or not that’s a good reason depends on who you ask.

The object orbits a brown dwarf that orbits a star, and astronomers aren’t sure if it’s a planet, a moon — or something else entirely.

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.

Pluto's demoted status as a dwarf planet turns 20 years old today and isn't even a chink in its armour when it comes to its ...

A rare type of plutonium has been found in the crust below the deep sea, offering new clues as to how heavy metals form in star explosions and mergers. Strange hexagonal diamonds may have been ...