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 ...

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

Scientists have unlocked one of the solar system's many secrets from an unexpected source: a planetarium show.

U.S. astronomers hunting for "Planet Nine" have instead stumbled on what appears to be a new dwarf planet in the solar system ...

Scientists' hunt for a mysterious planet at the edge of our solar system might have turned up results. A US-trio appears to ...

Even in our own solar system, distances seem infinite. Think of driving continuously at highway speed to Pluto. It would take ...