Miranda

Miranda is the smallest of Uranus's five major moons and arguably the most geologically bizarre body in the solar system. Its surface is a patchwork of ancient cratered terrain and sharply different "coronae" — oval regions of parallel ridges, troughs, and faults — joined along stark boundaries that look as though the moon was shattered and reassembled. One leading hypothesis is exactly that: a major impact disrupted Miranda billions of years ago and the fragments re-coalesced gravitationally before settling into a new equilibrium. Verona Rupes, a fault scarp on Miranda, drops 20 km — the tallest cliff known in the solar system.

Miranda is roughly 60% water ice and 40% rock. Its coronae — Inverness, Arden, and Elsinore — show flow-like features suggesting cryovolcanic resurfacing. The moon's low density and surface variety hint at a complex thermal history despite its small size.

Voyager 2 made the only close flyby of Miranda in January 1986, returning the only high-resolution images that exist. Most of what we know about Miranda comes from that single 1.5-hour encounter. No follow-up Uranus mission is currently scheduled, though NASA's Decadal Survey ranks a Uranus orbiter as a top priority for the 2030s.