Scientists may have discovered a dwarf planet far beyond Neptune — an unearthing that may disprove a longstanding theory ...

For the dwarf planet candidate, one trip around the sun takes over 24,000 years. Its orbit challenges a proposed path for a hypothetical Planet Nine.

A possible dwarf planet, like Pluto, has been observed in our solar system, according to a preprint published in arXiv. The area of space where this planet was found was previously thought empty.

Close stellar encounters could change the structure of our planetary system, potentially dooming Earth or other worlds to oblivion ...

The search for life beyond Earth is a holy grail quest for many experts, but finding where to look is a core issue.

OF201, the object belongs to the same all-star family as Pluto: dwarf planets. Its diameter, roughly 435 miles (700 km), is half Pluto’s, ...

The orange dwarf Gliese 710 is expected to come within 0.1663 light-years or 10,520 astronomical units in about 1.29 million ...