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

On Jan. 5, 2005, Eris was discovered. It was considered the largest known dwarf planet in the solar system until a year later ...

Potential discovery of new dwarf planet adds wrinkle to Planet Nine theory 017OF201 is a trans-Neptune object with a unique orbit located past the Kuiper Belt. By Nick Butler Fox News.

Pluto, the largest of those dwarf planets, has a diameter of about 1,477 miles (2,377 km). The mass of 2017 OF201 is estimated to be about 20,000 times smaller than Earth's and 50 times smaller ...

Earth has a newly-discovered neighbor in the solar system. But the heavenly body – possibly a dwarf planet à la Pluto – isn't a frequent visitor. Located beyond Neptune, its extreme orbit ...

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.