Beyond the familiar planets lies a fascinating frontier filled with icy worlds, mysterious orbits, and cosmic curiosities.

New models suggest that Ceres, the asteroid belt's largest object, once had a radioactive core that could have sustained life in the dwarf planet's hidden subsurface ocean billions of years ago.

Ceres, Eris, Makemake, Haumea, and Pluto are expected to have a new friend, Hygiea, inducted into our solar system’s dwarf planet club. Hygiea was long believed to be a large asteroid in the ...