What if Jupiter gained just a little bit more mass during its formation period, and then ignited to become a star? How ...

CNN — A large asteroid could be reclassified as a dwarf planet -- which could make it the smallest in the solar system -- after new research revealed it's shape, astronomers said on Monday. Nestled in ...

Two decades ago, Pluto was reclassified as a dwarf planet, sparking an enduring debate. NASA Administrator Jared Isaacman says he wants to “make Pluto a planet again.” ...

In the course of studying planets beyond our solar system (6,316 confirmed exoplanets and counting), scientists have discovered some very interesting systems. Consider TOI-201, a compact system ...

Artist’s impression of the surface of the dwarf planet Makemake (Credit: ESO/L. Calçada/Nick Risinger (skysurvey.org)) Astronomers have used three telescopes at ESO’s observatories in Chile to observe ...

A newly discovered cosmic object is not a planet, not a moon — but a third thing we don’t have a name for yet. The object is about as massive as Jupiter and orbits a brown dwarf — a body that fuses ...

Twenty years after Pluto lost its planetary status, the debate continues as scientists still disagree over what defines a planet.

WASHINGTON (Reuters) - Scientists have discovered the most distant object known in our solar system, so remote and unusual they chose the nickname "Farout" for the slow-moving, icy, pinkish dwarf ...