The researchers said 2017 OF201 was identified in observations by telescopes in Chile and Hawaii spanning seven years. Scientists have identified an object about 435 miles (700 km) wide inhabiting the ...

Astronomers have long been on the hunt for "Planet Nine," a hypothetical planet that lies within our solar system just beyond Neptune. Scientific evidence has alternately pointed to and against the ...

Is there a massive undiscovered planet on the outer reaches of the Solar System? The idea has been around since before the discovery of Pluto in the 1930s. Labelled as planet X, prominent astronomers ...

WASHINGTON (Reuters) -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 ...