Discovery of 2017OF201, a large trans-Neptune Object, challenges previous beliefs about the Kuiper Belt and hints at the existence of a theoretical Planet Nine.

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 ...

A series of studies have cast doubt on the sensational claim that "the strongest evidence yet" was found that life exists anywhere else besides Earth.

Scientists are intrigued after spotting a highly unusual celestial object lurking at the very edge of our solar system.

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

In the cold, distant reaches of the Solar System, far beyond Pluto, astronomers have just identified what could be a new ...

Astronomers have long been intrigued by the makeup of the asteroid belt’s largest body. When it was first spotted in 1801, ...

His reasoning: Neptune’s moon Triton is a near-twin of Pluto ... best assigned to a subcategory of “dwarf planets.” Just a year later, the first object (other than Pluto and Charon) was ...

Triton, the largest moon of Neptune ... reflecting both Pluto’s quirks and the affection for this dwarf planet discovered by Clyde Tombaugh in 1930. Uranus. Image by NASA via Unsplash. The seventh ...

The dwarf planet is a bizarre, cryovolcanic world. However, the organic deposits discovered on its surface so far are unlikely to originate from its interior. The organic material found in a few ...

A color-enhanced view of Ceres, the nearest dwarf planet to Earth, high­lights its Oc­ca­tor crater. Credit: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA Pluto is the most famous dwarf planet ...

Neptune’s largest moon, Triton, and the dwarf planet Pluto may have shared a common origin before being separated in the early solar system, an analysis of their composition suggests.