Ganymede is larger than the planet Mercury and is the only moon in the solar system known to possess its own magnetic field.

Europa, a moon of Jupiter, is believed to have a subsurface ocean beneath its icy crust, making it a potential hotspot for extraterrestrial life.

Titan is the only moon in the solar system with a dense atmosphere and stable bodies of surface liquid, such as methane lakes.

Phobos and Deimos are named after the Greek personifications of fear and dread, the twin sons of Ares, the Greek counterpart to the Roman god Mars.

Europa's subsurface ocean is kept liquid by tidal heating from Jupiter's gravity and may contain twice as much water as all of Earth's oceans combined.