Miranda (moon)

Miranda is the smallest and innermost of Uranus's five major moons. It was discovered on February 16, 1948, by astronomer Gerard Kuiper at the McDonald Observatory. Miranda is notable for its dramatically varied surface features, including huge fault canyons, terraced layers, and a patchwork of old and young surfaces. These features, collectively called "coronae," are unlike anything else seen in the solar system, leading to much scientific speculation about their formation.

Discovery and Naming

Miranda was named after the daughter of Prospero in William Shakespeare's play The Tempest. Like the other Uranian satellites, it is named after a character from Shakespeare or Alexander Pope.

Physical Characteristics

Miranda has a mean radius of approximately 235.8 kilometers (146.5 miles) and a density of about 1.2 g/cm³, indicating that it is composed primarily of water ice and silicate rock. Its surface gravity is extremely low.

Surface Features

The most distinctive feature of Miranda's surface is its coronae. The three identified coronae are Arden, Elsinore, and Inverness. These regions are characterized by complex geology, including ridges, grooves, and scarps. The origin of these structures is still debated, with various hypotheses including partial differentiation, tidal heating, and impact events. Verona Rupes, a massive cliff thought to be the tallest in the Solar System, is also found on Miranda.

Orbit

Miranda orbits Uranus at a distance of about 129,390 kilometers (80,400 miles), completing one orbit in approximately 1.4 Earth days. Its orbit is inclined by 4.338° to Uranus's equator, and it has a small eccentricity of 0.0013.

Exploration

The only spacecraft to have visited Miranda is Voyager 2, which flew by the moon in January 1986. Voyager 2 captured images of Miranda's surface, revealing the dramatic geological features that make it such an intriguing object of study. No further missions to Uranus or its moons have been planned as of 2024.

Formation Theories

Several theories have been proposed to explain Miranda's unusual geology. One popular theory suggests that Miranda may have been shattered by a massive impact and then reassembled, with the different pieces ending up in a jumbled configuration. Another theory involves partial differentiation within Miranda, with denser material sinking to the core and lighter material rising to the surface. Tidal heating, caused by gravitational interactions with Uranus and other moons, may have also played a role in shaping Miranda's surface.