OF201, a distant dwarf planet candidate with a rare orbit that questions the existence and stability of the Planet Nine theory.

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 new memorandum has firmed up China and Russia's intent to lead the construction of a new lunar base to be completed by 2036, as NASA talks about scaling back its own lunar ambitions.