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'Miranda' () is the smallest and innermost of Uranus' five major moons.
It was discovered by Gerard Kuiper on 1948-02-16 at McDonald Observatory. It was named after Prospero's daughter in William Shakespeare's play ''The Tempest'' by Kuiper in his report of the discovery.^[1] The adjectival form of the name is ''Mirandan''. It is also designated 'Uranus V'.
So far the only close-up images of Miranda are from the ''Voyager 2'' probe, which made observations of the moon during its Uranus flyby in January, 1986. During the flyby the southern hemisphere of the moon was pointed towards the Sun so only that part was studied. It is geologically the most active body in the Uranian system.

Contents

Physical characteristics

Miranda in popular culture

See also

References

External links

Physical characteristics

Miranda's surface may be mostly water ice, with the low density body also likely containing silicate rock and organic compounds in its interior.
Miranda's surface has patchwork regions of broken terrain indicating intense geological activity in the moon's past, and is criss-crossed by huge canyons. Large grooved structures, called coronae, may be diapirs, or upwellings of warm ice. The grooves probably represent cryovolcanic ridges formed by fissure eruptions of icy magma. The canyons probably represent grabens formed by extensional faulting. The diapirs may have changed the density distribution within the moon, which could have caused Miranda to reorient itself,^[3] an event similar to what is believed to have occurred on Saturn's geologically active moon Enceladus. Miranda is one of the few bodies in the solar system in which the equatorial circumference is shorter than the pole-to-pole circumference, likely a consequence of the diapir activity.
Miranda's past geological activity is believed to have been driven by tidal heating at a time when its orbit was more eccentric than currently. Early in its history, Miranda was apparently captured in a 3:1 orbital resonance with Umbriel, from which it subsequently escaped.^[4] The resonance would have increased orbital eccentricity; resulting tidal friction due to time-varying tidal forces from Uranus would have caused warming of the moon's interior. In the Uranus system, due to the planet's lesser degree of oblateness, and the larger relative size of its satellites, escape from a mean motion resonance is much easier than for satellites of Jupiter or Saturn. Miranda's orbital inclination (4.34°) is unusually high for a body so close to the planet. Miranda probably escaped from its resonance with Umbriel via a secondary resonance, and the mechanism of this escape is believed to explain why its orbital inclination is more than 10 times those of the other large Uranian moons (see Uranus' natural satellites).^[5][6]
An earlier theory, proposed shortly after the ''Voyager 2'' flyby and now out of favor, was that a previous incarnation of Miranda was shattered by a massive impact, with the fragments reassembling into the current strange pattern.^[7]
Scientists recognize the following geological features on Miranda:

★ Craters

★ Coronae (large ovoid features)

★ Regiones (geological regions)

★ Rupes (scarps)

★ Sulci (parallel grooves)

Miranda in popular culture

★ Astronomy Domine, a song by Pink Floyd, refers to Miranda as well as Oberon and Titania.

★ In the fictional Star Trek universe, the crystalline mineral dilithium was first discovered on Miranda in the mid-21st century. The moon said to be the only naturally occurring source of dilithium in the Sol system. This mineral was, a short time later, used to facilitate warp drive propulsion systems which allowed spacecraft to achieve faster-than-light travel.

See also

★ List of geological features on Miranda

References

1. G. P. Kuiper, ''The Fifth Satellite of Uranus'', Publications of the Astronomical Society of the Pacific, Vol. 61, No. 360, p. 129, June 1949
2. PIA00044: Miranda high resolution of large fault
3.
4. Tidal evolution of the Uranian satellites III. Evolution through the Miranda-Umbriel 3:1, Miranda-Ariel 5:3, and Ariel-Umbriel 2:1 mean-motion commensurabilities, , William C., Tittemore, Icarus,
5. Tidal Evolution of the Uranian Satellites II. An Explanation of the Anomalously High Orbital Inclination of Miranda, W. C. Tittemore, J. Wisdom, , , Icarus, 1989
6. The Role of Secondary Resonances in the Orbital History of Miranda, R. Malhotra, S. F. Dermott, , , Icarus, 1990
7. Birth of Uranus' provocative moon still puzzles scientists

External links

★ Miranda Profile by NASA's Solar System Exploration

★ Miranda page on ''The Nine8 Planets''

★ Miranda, A Moon of Uranus on ''Views of the Solar System''