Editing Icy moon

{{Short description|Natural satellite with a surface mainly composed of ice}}
'''Icy moons''' are a class of [[natural satellite]]s 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.<ref>{{cite journal | title=The Physical Oceanography of Ice-Covered Moons | display-authors=1 | last1=Soderlund | first1=Krista M. | last2=Rovira-Navarro | first2=Marc | last3=Le Bars | first3=Michael | last4=Schmidt | first4=Britney E. | last5=Gerkema | first5=Theo | journal=Annual Review of Marine Science | volume=16 | pages=25–53 | date=January 2023 | doi=10.1146/annurev-marine-040323-101355 | bibcode=2023ARMS...16...25S }}</ref> It is thought that they may be composed of [[ice II]] or other [[Polymorphism (materials science)|polymorph]] of water ice.<ref name="Ice_II_structure">{{cite web |url=http://www.lsbu.ac.uk/water/ice_ii.html |title=Ice-two structure |accessdate=2008-01-02 |author=Chaplin, Martin |date=2007-10-26 |work=Water Structure and Science}}</ref> The prime example of this class of object is [[Europa (moon)|Europa]].

Icy moons warmed by [[tide]]s may be the most common type of [[celestial body]] in the galaxy to have liquid [[water]],<ref>{{Cite web |date=2024-10-12 |title=Can Life Exist on an Icy Moon? NASA’s Europa Clipper Aims to Find Out - NASA |url=https://www.nasa.gov/missions/europa-clipper/can-life-exist-on-an-icy-moon-nasas-europa-clipper-aims-to-find-out/ |access-date=2024-11-18 |language=en-US}}</ref> and thus the most likely type of object to possibly have [[water]]-based [[extraterrestrial life|life]].

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

==Orbits==
Most known large icy moons belong to [[giant planet]]s, whose orbits lie beyond the Solar System's [[Frost line (astrophysics)|frost line]]; the remainder (such as [[Charon (moon)|Charon]] and [[Dysnomia (moon)|Dysnomia]]) formed around dwarf planets such as [[Pluto]] and {{dp|Eris}}, typically in large impacts not unlike the impact thought to have formed Earth's moon. In the case of icy gas giant satellites, 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 (moon)|Europa]] is thought to contain 8% ice and water by mass with the remainder rock.<ref name="arxiv0812">{{cite book |arxiv= 0812.4995 |author1= Canup, Robin M. |author1-link=Robin Canup |author2= Ward, William R. |authorlink2=William Ward (astronomer) |title= Origin of Europa and the Galilean Satellites |year=2008 |bibcode= 2009euro.book...59C |page= (page needed) }}</ref>  Jupiter's outer two [[Galilean moons]] [[Ganymede (moon)|Ganymede]] and [[Callisto (moon)|Callisto]] contain more ice since they formed further from the hot proto-Jupiter.

Saturn's moon [[Titan (moon)|Titan]] looks and behaves more like Earth than any other body in the Solar System.<ref name="IAU0915">{{cite web
  |date=2009-08-06
  |title=Surface features on Titan form like Earth's, but with a frigid twist
  |publisher=[[IAU]]
  |author1=Rosaly Lopes |author1-link=Rosaly Lopes |author2=Robert M. Nelson |url=http://www.iau.org/public_press/news/detail/iau0915/
  |accessdate=2009-12-21}}</ref>  Titan is known to have stable pools of [[liquid methane]] on the surface.<ref name="IAU0915"/>

==Images==
<gallery>
Image:PIA01130 Interior of Europa.jpg|[[Europa (moon)|Europa]] is thought to have a [[Europa (moon)#Subsurface ocean|subsurface ocean]]
Image:Ganymede-moon.jpg|False-color image of [[Ganymede (moon)|Ganymede]]
Image:Callisto_-_July_8_1979_(38926064465).jpg|[[Callisto (moon)|Callisto]] showing frost [[deposit (geology)|deposits]]
Image:Mimas moon.jpg|[[Mimas (moon)|Mimas]] has a density of 1.1&nbsp;g/cm<sup>3</sup>
Image:Successful Flight Through Enceladus Plume.jpg|Active plumes on [[Enceladus]]
Image:Titan multi spectral overlay.jpg|False-color image of [[Titan (moon)|Titan]] showing surface and atmospheric details
Image:Miranda - January 24 1986 (30906319004).jpg|[[Miranda (moon)|Miranda]] has a scarred surface
File:PIA00040 Umbrielx2.47.jpg|A potential frost deposit on [[Umbriel|Umbriel's]] pole
Image:Tritoncloud.jpg|A cloud over the limb of [[Triton (moon)|Triton]]
</gallery>

==See also==
*[[Ocean planet]]
*[[Ice planet]]
*[[Tectonics on icy moons]]

== References ==
{{reflist}}

{{Solar System moons (compact)}}

{{DEFAULTSORT:Icy Moon}}
[[Category:Moons]]
[[Category:Water ice|Moon]]