Icy moon

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Icy moons are a class of natural satellites with surfaces composed mostly of ice. An icy moon may harbor an ocean underneath the surface, and possibly include a rocky core of silicate or metallic rocks. It is thought that they may be composed of ice II or other polimorph of water ice.[1] The prime example of this class of object is Europa.

Icy moons warmed by tides may be the most common type of object to have liquid water,[citation needed] and thus the type of object most likely to have water-based life.[dubious ]

Some icy moons exhibit cryovolcanism, as well as geysers. The best studied example is Saturn's Enceladus.

Orbits[edit]

All known icy moons belong to giant planets, whose orbits lie beyond the Solar System's frost line. An additional requirement is that a moon did not form in the inner region of a proto-satellite disk, which is too warm for ices to condense.

Europa is thought to contain 8% ice and water by mass with the remainder rock.[2] Jupiter's outer two Galilean moons Ganymede and Callisto contain more ice since they formed further from the hot proto-Jupiter.

Saturn's moon Titan looks and behaves more like Earth than any other body in the Solar System.[3] Titan is known to have stable pools of liquid on the surface.[3]

Images[edit]

References[edit]

  1. ^ Chaplin, Martin (2007-10-26). "Ice-two structure". Water Structure and Science. Retrieved 2008-01-02. 
  2. ^ Canup, Robin M.; Ward, William R. (2008). "Origin of Europa and the Galilean Satellites". Astrophysical Journal. arXiv:0812.4995. Bibcode:2009euro.book...59C. 
  3. ^ a b Rosaly Lopes and Robert M. Nelson (2009-08-06). "Surface features on Titan form like Earth’s, but with a frigid twist". IAU. Retrieved 2009-12-21.