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.

It had not been thought possible that such tiny, weak stars could provide the conditions needed to form and host huge planets.

A sweeping new ICE operation shows how Donald Trump’s focus on immigration is reshaping federal law enforcement.

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

The discovery challenges the Planet Nine hypothesis, which suggests a massive, unseen planet is influencing the orbits of distant TNOs. While most extreme TNOs show a clustered pattern that supports ...

A recently discovered celestial body is rewriting our knowledge of the Kuiper Belt and maybe challenging the existence of the ...

This is one of these messy lesser-of-two-evils arguments I usually try to steer clear of because I can see that ‘less harm’ (and I will argue here that the ‘less harm’ claim is far from settled) is ...

Less than 1% of this dwarf planet candidate's orbit is close enough to detect, which means astronomers are lucky to have ...

Researchers discovered a new trans-Neptunian object, 2017 OF201, potentially a dwarf planet, in the outer 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 ...

A potential new dwarf planet has been discovered in the outer reaches of the solar system, and its existence poses the ...

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