Enceladus
Enceladus is a small, highly reflective icy moon of Saturn, about 504–505 km across, noted for active cryovolcanic plumes that vent material from a global subsurface ocean. Discovered in 1789 by William Herschel, it orbits Saturn every 32.9 hours in a 2:1 resonance with Dione, a configuration that helps sustain internal tidal heating and geological activity.
