DESCRIPTION AND
DATA SHEET

Inverness Corona
Miranda, Uranus

This Voyager 2 stereo view of the small icy Uranian satellite Miranda was obtained in 1986 and is probably the best stereo view of an icy satellite obtained during this mission. Despite its tiny size, only 470 kilometers across, Miranda has had a surprisingly diverse and complex geologic history.

Most of the interesting geologic features on Miranda are concentrated in three oval- to square-shaped regions called coronae. Coronae can be up to 300 kilometers across and consist of a central zone of chaotic ridges surrounded by a zone of concentric ridges and fractures. Ridges appear to be extensional faults in some areas and volcanic extrusions in other areas. These volcanic ridges may be composed of ammonia-water. One fault scarp (not shown here) is nearly 10 kilometers high.

The concentric pattern of volcanism and tectonism within coronae suggest that they formed over plumes of material rising from the core of Miranda. These plumes spread out as they neared the surface, fracturing the crust and triggering local volcanism.

The geologic complexity of Miranda is puzzling because it should have been cold and quiescent (inactive) since shortly after its formation. The heat required to melt large parts of the interior may have been provided by tidal interactions with neighboring satellites and Uranus itself. Similar tidal heating powers the volcanos on Jupiter's moon Io (such as Prometheus) and may be responsible for the resurfacing of Ariel.

Location:
     75.0 S, 40.0 E
Mission:
     Voyager 2
Image Numbers:
     26846.11, 26846.14, 26846.26
Image Resolution
(Full-Sized View):
     310 meters/pixel
Image Width:
     ~230 kilometers
Vertical Exaggeration:
     1.6 × Normal
Vertical Resolution:
     225 meters
Spacecraft Altitude:
     31,000 kilometers
Convergence Angle:
     16°