Look to the southeastern horizon in the hours following sunset on Nov. 29 — you'll be able to see the moon shine close to the gas giant Saturn as Neptune lurks unseen nearby. The waxing gibbous moon ...

Small icy moons may have hidden oceans that briefly boil under thick ice. Changing pressure inside these moons shapes their ...

Rather than flowing magma, geological shifts on icy moons are produced by melting ice. The ice shells coating these moons wax ...