Miranda (satelit)

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Stampa:Infobox planet

Miranda është nje nga pese henat e medhate, dhe pikerisht ajo me më e thellë dhe më e vogla e Uranit.

Ajo u zbulua nga Gerard Kuiper ne shkurt 16, 1948 ne McDonald Observatory. Ajo u emërua sipas Miranda nga pjesa e William Shakespeare Shtrëngata nga Kuiper në raportin e tij të zbulimit.[1] Forma ndajfoljore e fjales është Mirandan. Ky satelit është dizajnuar edhe per Uranus V.

Deri tani të vetmet imazhe të afërt- të Miranda janë nga provat e Voyager 2 ,e cila bëri vëzhgimet e ketij sateliti qe ndonjehere uhet edhe hënë gjatë fluturimit per te Urani në janar 1986. Gjatë fluturimit mbi hemisferen jugore te hënës u drejtua drejt diellit kështu që vetëm ajo pjesë është studiuar. Miranda tregon më shumë dëshmi të veprimtarisë së kaluar gjeologjike se çdo të satelit tjetër Uranian.

Karakteristikat fizike[redakto | përpunoni burim]

Close-up view of Verona Rupes, a large fault scarp on Miranda; possibly 5 km (3.1 mi) high.[2][3]

Miranda's surface may be mostly water ice, with the low-density body also probably 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 'racetrack'-like grooved structures, called coronae, may have formed via extensional processes at the tops of diapirs, or upwellings of warm ice.[3][4] The ridges probably represent extensional tilt blocks. The canyons probably represent graben formed by extensional faulting. Other features may be due to cryovolcanic eruptions of icy magma. The diapirs may have changed the density distribution within the moon, which could have caused Miranda to reorient itself,[5] similar to a process believed to have occurred at Saturn's geologically active moon Enceladus.

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 into a 3:1 orbital resonance with Umbriel, from which it subsequently escaped.[6] 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 Uranian 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 moons of Uranus).[7][8]

Miranda may have also once been in a 5:3 resonance with Ariel, which would have also contributed to its internal heating. However, the maximum heating attributable to the resonance with Umbriel was likely about three times greater.[6]

An earlier theory, proposed shortly after the Voyager 2 flyby, was that a previous incarnation of Miranda was shattered by a massive impact, with the fragments reassembling and denser ones subsequently sinking to produce the current strange pattern.[3]

Approaching the 2007-12-07 equinox Miranda produced brief solar eclipses over the center of Uranus.

Scientists recognize the following geological features on Miranda:

Shih edhe[redakto | përpunoni burim]


Referenca[redakto | përpunoni burim]

  1. ^ Kuiper, G. P., 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". JPL, NASA. Marrë më 2007-07-23. 
  3. ^ a b c Chaikin, Andrew (2001-10-16). "Birth of Uranus' Provocative Moon Still Puzzles Scientists". Space.com. Imaginova Corp. Arkivuar nga origjinali më 2001-11-08. Marrë më 2007-12-07. [lidhje e thyer]
  4. ^ Stampa:Cite doi
  5. ^ Pappalardo, Robert T.; Greeley, Ronald (1993). "Structural evidence for reorientation of Miranda about a paleo-pole". In Lunar and Planetary Inst., Twenty-Fourth Lunar and Planetary Science Conference. Part 3: N-Z. f. 1111–1112. Marrë më 2006-08-05. 
  6. ^ a b Stampa:Cite doi
  7. ^ Stampa:Cite doi
  8. ^ Stampa:Cite doi

Gabim referencash: <ref> etiketa me emrin "Thomas 1988" e percaktuar ne <referenca> nuk është përdorur në tekst paraprak.
Gabim referencash: <ref> etiketa me emrin "Jacobson Campbell et al. 1992" e percaktuar ne <referenca> nuk është përdorur në tekst paraprak.
Gabim referencash: <ref> etiketa me emrin "Hanel Conrath et al. 1986" e percaktuar ne <referenca> nuk është përdorur në tekst paraprak.

Gabim referencash: <ref> etiketa me emrin "jplssd" e percaktuar ne <referenca> nuk është përdorur në tekst paraprak.

Lidhje te jashtme[redakto | përpunoni burim]

Stampa:Uranus Stampa:Moons of Uranus Stampa:Solar System moons (compact)