A possible new dwarf planet has been discovered at the edge of our solar system, so far-flung that it takes around 25,000 ...

As it orbits the sun once every 25,000 years, the celestial body 2017 OF201 travels beyond the Kuiper Belt into a region ...

A new dwarf planet, discovered beyond Neptune and described as Pluto's 'cousin,' could void the hypothesis of a Planet X in ...

The small world was found during a search for the hypothetical Planet Nine, and astronomers say the next time it will reach ...

Plus, an in-depth look at how the West Texas city of Seminole reacted when a measles outbreak tore through the region.

There’s a new object in the distant reaches of our solar system, and it might just offer clues to a long-standing cosmic ...

A team of astronomers believe they may have discovered a new dwarf planet—just like Pluto—on the edge of our solar system.

Scientists have identified an object about 435 miles (700 km) wide inhabiting the frigid outer reaches of our solar system that might qualify as a dwarf planet, spotting it as it travels on a highly ...

The International Astronomical Union’s Minor Planet Center, which catalogs new moons and other small bodies in the solar ...

There’s a new frozen oddball orbiting the Sun, and it’s not your average space rock. It’s a planet—a minor one, to be ...

As explained in a pre-press paper [PDF] titled “Discovery of a dwarf planet candidate in an extremely wide orbit: 2017 OF201” ...

Astronomers have found a new minor planet beyond Pluto. This object, named 2017 OF201, is quite large. It orbits far from the ...