Dwarf planet 2023 KQ14, Ammonite, has a stable orbit that challenges the hypothesis of the mysterious Planet Nine.

The solar system lost its ninth planet back when Pluto was demoted to a dwarf planet, but research might indicate that there ...

For years, astronomers have been excited about the idea that some planets beyond our solar system might be covered by vast, ...

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit before shoving four of the solar system's planets onto a different course. When ...

The official number of exoplanets—planets outside our solar system—tracked by NASA has reached 6,000. Confirmed planets are ...