Moons · Space Codex
Miranda
The smallest and innermost of Uranus's five major moons looks stitched together from mismatched pieces, with canyons up to 12 times deeper than the Grand Canyon.
A patchwork moon with record cliffs
At a glance
Key points
- Canyons up to 12× deeper than the Grand Canyon
- A rock would fall for 10 minutes from its highest cliff
- Seen up close only once, by Voyager 2 in 1986
Surface
Voyager 2's January 1986 images showed old, cratered terrain broken by three huge 'coronae', lightly cratered tracts of parallel ridges and grooves with sharp outlines. Fault canyons drop up to 12 times deeper than the Grand Canyon, and in Miranda's feeble gravity a rock dropped from the highest cliff would fall for about ten minutes.
Exploration
Voyager 2 is the only spacecraft to have visited, passing on 24 January 1986. Uranus was near solstice, so only the southern hemispheres of its moons were in sunlight; the northern halves have never been seen up close.
What we still don't know
What resurfaced such a small, cold moon. Ideas range from tidal heating in a past orbital resonance to upwelling of warm ice; some researchers have suggested Miranda may once have had an ocean.
Missions
- 1977–
The only spacecraft to visit Uranus (1986) and Neptune (1989); interstellar since 5 Nov 2018.
First-hand · our 3D model
How we render it
Miranda is a sphere wrapped in a global map built from USGS and NASA spacecraft mosaics. Voyager 2 imaged only one hemisphere, so the unseen side is a feathered procedural fill.
It is drawn at about 4.3% of Uranus's radius, enlarged from its true 0.93% so it stays visible. It orbits in Uranus's equatorial frame, inclined 4.4°, with a 1.41-day period kept in true ratio to its neighbours, and keeps one face towards Uranus.
Moon sizes and orbits are compressed so a whole system fits on screen, but never reordered: each moon is drawn at 0.72 × (true size ratio)^0.6 of its planet, capped so no large moon is drawn bigger than it really is, and orbit distances are log-compressed into a band that clears the planet's rings. Orbital periods keep their true ratios, every moon is tidally locked, and on lighter devices only the two largest moons of each planet are drawn.
Related entries
Sources
- JPL Solar System Dynamics: satellite physical parameters (opens in a new tab)
- JPL Solar System Dynamics: satellite mean orbital elements (opens in a new tab)
- NASA NSSDC Uranian Satellite Fact Sheet (opens in a new tab)
- NASA Science: Miranda (opens in a new tab)
Last reviewed against these sources. Built from public NASA, ESA and JPL data; not affiliated with or endorsed by any agency.