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 ...

That was one of the main reasons for Pluto's demotion from planet to dwarf planet in 2006. New Horizons measured Pluto as being two kilometres wider than thought, pushing it past Eris, but there's ...

For years, astronomers have been searching for a ninth planet in our solar system (after giving Pluto the old heave-ho and demoting it to a dwarf planet) and now researchers say they’ve found a ...

There have been questions about a mysterious ninth planet in our solar system for nearly a decade. Pluto was unseated as number nine in 2006. Now, a group of international researchers say they may ...

There have been questions about a mysterious ninth planet in our solar system for nearly a decade. Pluto was unseated as number nine in 2006. Now, a group of international researchers say they may ...

A new look through decades-old data has unveiled some of the most compelling evidence yet of a hidden ninth planet in the far reaches of our solar system, far beyond ...

So many unexplored secrets still lie at the outskirts of our solar system, where a potential candidate for a new dwarf planet lies. Although space beyond Neptune was thought to be mostly devoid of ...

For now, the outer reaches of our 4.6 billion-year-old solar system continue to be shrouded in mystery, with the classification of objects changing as scientists gain a new understanding of them ...

But are these really "planets," or was Pluto merely the first discovery of an entirely new class of objects? In 2006, the International Astronomical Union, the gatekeepers of astronomical nomenclature ...

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 ...