The International Astronomical Union’s Minor Planet Center, which catalogs new moons and other small bodies in the solar ...

Astronomers have discovered a mysterious dwarf planet, 2017 OF201, far beyond Pluto. This discovery challenges existing ...

There’s a new frozen oddball orbiting the Sun, and it’s not your average space rock. It’s a planet—a minor one, to be ...

A US-based trio hunting this elusive world has stumbled on what appears to be a new dwarf planet in the solar system's outer ...

A new dwarf planet discovery in the outer solar system is challenging the long-standing theory of a hidden giant planet ...

It's an evocative idea that has long bedeviled scientists: a huge and mysterious planet is lurking in the darkness at the ...