View source for Ananke (moon)

{{short description|Moon of Jupiter}}
{{Use dmy dates|date=November 2020}}
{{Infobox planet
| name = Ananke
| image = Ananké.jpg
| caption = Ananke photographed by the [[Haute-Provence Observatory]] in August 1998
| pronounced = {{IPAc-en|ə|ˈ|n|æ|ŋ|k|iː}}<ref>{{Dict.com|Ananke}}</ref>
| adjective = Anankean {{IPAc-en|æ|n|ə|ŋ|ˈ|k|iː|ə|n}}<ref>Yenne (1987) ''The Atlas of the Solar System''.</ref>
| named_after = [[Ananke (mythology)|Ἀνάγκη]] ''Ana<!--sic-->gkē''
| mpc_name = Jupiter XII
| alt_names = 
| discovery_ref = <ref name="Nicolson1951"/>
| discoverer = [[Seth Barnes Nicholson|Seth B. Nicholson]]
| discovery_site = [[Mount Wilson Observatory|Mt. Wilson Observatory]]
| discovered = 28 September 1951
| earliest_precovery_date = 
| satellite_of = [[Jupiter]]
| group = [[Ananke group]]
| orbit_ref = <ref name="MPC127087"/>
| epoch = 17 December 2020 ([[Julian day|JD]] 2459200.5)
| observation_arc = 69.05 [[Julian year (astronomy)|yr]] (24,338 days)
| semimajor = {{cvt|0.1406602|AU|km|lk=in}}
| eccentricity = 0.1747248
| period = –623.59 d
| mean_anomaly = 339.61045[[Degree (angle)|°]]
| mean_motion = {{Deg2DMS|0.57730026|sup=ms}} / day
| inclination = 148.67482° (to [[ecliptic]])
| asc_node = 86.44368°
| arg_peri = 135.63033°
| mean_diameter = {{val|29.1|0.6|u=km}}<ref name="Grav2015"/>
| mass = {{val|1.68|e=16|u=kg}} (calculated)
| density = 1.30 g/cm<sup>3</sup> (assumed)<ref>{{Cite journal |last1=Chen |first1=Zhenghan |last2=Yang |first2=Kun |last3=Liu |first3=Xiaodong |date=2024-02-06 |title='Life' of dust originating from the irregular satellites of Jupiter |journal=Monthly Notices of the Royal Astronomical Society |volume=527 |issue=4 |pages=11327–11337 |doi=10.1093/mnras/stad3829 |doi-access=free |language=en |arxiv=2402.03680}}</ref>
| surface_grav = 
| escape_velocity = 
| rotation = {{val|8.31|0.15|ul=h}}<ref name="Luu1991"/>
| albedo = {{val|0.038|0.006}}<ref name="Grav2015"/>
| magnitude = 18.9<ref name="SheppardMoons"/>
| abs_magnitude = 11.7<ref name="MPC127087"/>
}}

'''Ananke''' ({{IPAc-en|ə|ˈ|n|æ|ŋ|k|i}}) is a [[retrograde motion|retrograde]] [[irregular satellite|irregular]] [[Moons of Jupiter|moon of Jupiter]]. It was discovered by [[Seth Barnes Nicholson]] at [[Mount Wilson Observatory]] in 1951.<ref name="Nicolson1951">{{cite journal|last=Nicholson|first=S. B.| url=http://adsabs.harvard.edu//full/seri/PASP./0063//0000297.000.html|title=An unidentified object near Jupiter, probably a new satellite|journal=Publications of the Astronomical Society of the Pacific|volume=63|issue=375|date=1951|pages=297–299|doi=10.1086/126402|bibcode=1951PASP...63..297N|doi-access=free}}</ref> It is named after the Greek mythological [[Ananke (mythology)|Ananke]], the personification of necessity, and the mother of the [[Moirai]] (Fates) by [[Zeus]]. The adjectival form of the name is ''Anankean''.<!-- Google it: two hits, albeit non-astronomical -->

Ananke did not receive its present name<ref name="Nicholson1938">{{cite journal |last=Nicholson |first=S.B. |date=April 1939 |title=The Satellites of Jupiter |url=http://adsabs.harvard.edu//full/seri/PASP./0051//0000093.000.html |journal=Publications of the Astronomical Society of the Pacific |volume=51 |issue=300 |pages=85–94 |bibcode=1939PASP...51...85N |doi=10.1086/125010 |doi-access=free}}</ref> until 1975;<ref name="IAUC 2846">{{cite journal| last=Marsden|first=B. G.|title=Satellites of Jupiter|journal=IAU Circular |volume=2846|date=7 October 1974|url=http://www.cbat.eps.harvard.edu/iauc/02800/02846.html}}</ref> before then, it was simply known as '''{{nowrap|Jupiter XII}}'''. It was sometimes called "Adrastea"<ref name="Gaposchkin">{{cite book| last=Payne-Gaposchkin|first=Cecilia|author2=Katherine Haramundanis|title=Introduction to Astronomy|date=1970|publisher=[[Prentice-Hall]]|location=Englewood Cliffs, N.J.|isbn=0-13-478107-4}}</ref> between 1955 and 1975 (Adrastea is now the name of [[Adrastea (moon)|another satellite of Jupiter]]).

Ananke gives its name to the [[Ananke group]], retrograde irregular moons which orbit Jupiter between 19.3 and 22.7 Gm, at inclinations of roughly 150°.<ref name="SheppardJewittPorco2004">[[Scott S. Sheppard|Sheppard, S. S.]], [[David C. Jewitt|Jewitt, D. C.]], [[Carolyn Porco|Porco, C.]]; [http://www.ifa.hawaii.edu/~jewitt/papers/JUPITER/JSP.2003.pdf ''Jupiter's Outer Satellites and Trojans''] {{webarchive|url=https://web.archive.org/web/20070614045102/http://www.ifa.hawaii.edu/~jewitt/papers/JUPITER/JSP.2003.pdf |date=2007-06-14 }}, in ''Jupiter: The Planet, Satellites and Magnetosphere,'' edited by Fran Bagenal, Timothy E. Dowling, William B. McKinnon, Cambridge Planetary Science, Vol. 1, Cambridge, UK: Cambridge University Press, {{ISBN|0-521-81808-7}}, 2004, pp. 263-280</ref>

==Orbit==
[[Image:TheIrregulars JUPITER retro.svg|thumb|left|300px|Retrograde irregular satellites of Jupiter.]]
Ananke orbits Jupiter on a high-eccentricity and high-inclination retrograde orbit. Fifteen irregular satellites orbiting Jupiter have been discovered since 2000 following similar orbits.<ref name="SheppardJewittPorco2004"/> The orbital elements are as of January 2000.<ref name="Jacobson 2000">{{cite journal |last=Jacobson |first=R. A. |author-link=Robert A. Jacobson |date=2000 |title=The Orbits of the Outer Jovian Satellites |url=https://trs.jpl.nasa.gov/bitstream/2014/15175/1/00-1187.pdf |journal=Astronomical Journal |volume=120 |issue=5 |pages=2679–2686 |bibcode=2000AJ....120.2679J |doi=10.1086/316817 |s2cid=120372170}}</ref> They are continuously changing due to [[Sun|solar]] and planetary perturbations. The diagram illustrates Ananke's orbit in relation to other retrograde irregular satellites of Jupiter. The eccentricity of selected orbits is represented by the yellow segments (extending from the [[apsis|pericentre]] to the [[apsis|apocentre]]). The outermost regular satellite [[Callisto (moon)|Callisto]] is located for reference.

Given these orbital elements and the physical characteristics known so far,  Ananke is thought to be the largest remnant<ref name="SheppardJewitt2003">{{cite journal|last=Sheppard |first=S.S. |author2=Jewitt, D.C. |title=An abundant population of small irregular satellites around Jupiter |journal=Nature |volume=423 |date=2003 |pages=261–263 |doi=10.1038/nature01584 |pmid=12748634 |issue=6937 |url=http://www.ifa.hawaii.edu/~jewitt/papers/JSATS/SJ2003.pdf |bibcode=2003Natur.423..261S |s2cid=4424447 |url-status=dead |archive-url=https://web.archive.org/web/20060813235622/http://www.ifa.hawaii.edu/~jewitt/papers/JSATS/SJ2003.pdf |archive-date=August 13, 2006 }}</ref> of an original break-up, forming the [[Ananke group]].<ref name="Nesvorny2004">
{{cite journal|last=Nesvorný|first=D.|author2=Beaugé, C.|author3=Dones, L.|title=Collisional Origin of Families of Irregular Satellites| journal=The Astronomical Journal|volume=127|issue=3|date=2004|pages=1768–1783|url=http://www.iop.org/EJ/article/1538-3881/127/3/1768/203442.html|doi=10.1086/382099|bibcode=2004AJ....127.1768N|doi-access=free}}</ref><ref name="Grav2003">{{cite journal|last=Grav|first=Tommy|title=Photometric survey of the irregular satellites|journal=Icarus|volume=166|issue=1|date=2003|pages=33–45|doi=10.1016/j.icarus.2003.07.005|author2=Holman, M. J.|author3= Gladman, B. J.|author4= Aksnes, K.|bibcode=2003Icar..166...33G|arxiv = astro-ph/0301016 |s2cid=7793999}}</ref>

==Physical characteristics==
[[File:Ananke WISE-W3.jpg|thumb|left|upright|Single-exposure image of Ananke by the [[Wide-field Infrared Survey Explorer]] (WISE) spacecraft in 2010]]
In the visible [[electromagnetic spectrum|spectrum]], Ananke appears neutral to light-red ([[color index|colour indices]] B-V=0.90 V-R=0.38).<ref name="Grav2003"/>

The [[infrared]] spectrum is similar to [[P-type asteroid]]s but with a possible indication of water.<ref name="Grav2004">{{cite journal|last1=Grav|first1=Tommy|last2=Holman|first2=Matthew J.|title=Near-Infrared Photometry of the Irregular Satellites of Jupiter and Saturn|journal=The Astrophysical Journal|volume=605|issue=2|date=2004|pages=L141–L144| arxiv=astro-ph/0312571|doi=10.1086/420881|bibcode=2004ApJ...605L.141G|s2cid=15665146}}</ref>

{{clear}}

==See also==
{{Portal|Astronomy}}
* [[Irregular satellite]]s

==References==
{{reflist|refs=

<ref name="MPC127087">{{cite web
  |title      = M.P.C. 127087
  |url        = https://minorplanetcenter.net/iau/ECS/MPCArchive/2020/MPC_20201117.pdf
  |work       = Minor Planet Circular
  |publisher  = Minor Planet Center
  |date       = 17 November 2020}}</ref>

<ref name="SheppardMoons">{{cite web
  |title      = Scott S. Sheppard - Jupiter Moons
  |url        = https://sites.google.com/carnegiescience.edu/sheppard/moons/jupitermoons
  |last       = Sheppard |first = Scott
  |work       = Department of Terrestrial Magnetism 
  |publisher  = Carnegie Institution for Science
  |access-date = 26 November 2020}}</ref>

<ref name="Luu1991">{{cite journal
  |first      = Jane |last = Luu
  |date       = September 1991
  |title      = CCD photometry and spectroscopy of the outer Jovian satellites
  |journal    = Astronomical Journal
  |volume     = 102
  |pages      = 1213–1225
  |issn       = 0004-6256
  |doi        = 10.1086/115949
  |bibcode    = 1991AJ....102.1213L}}</ref>

<ref name="Grav2015">{{cite journal
  |display-authors = etal
  |first1     = T. |last1 = Grav
  |first2     = J. M. |last2 = Bauer
  |first3     = A. K. |last3 = Mainzer
  |first4     = J. R. |last4 = Masiero
  |first5     = C. R. |last5 = Nugent
  |first6     = R. M. |last6 = Cutri
  |date       = August 2015
  |title      = NEOWISE: Observations of the Irregular Satellites of Jupiter and Saturn
  |journal    = The Astrophysical Journal
  |volume     = 809
  |issue      = 1
  |id         = 3
  |pages      = 9
  |doi        = 10.1088/0004-637X/809/1/3
  |arxiv = 1505.07820 |bibcode    = 2015ApJ...809....3G|s2cid = 5834661 }}</ref>

}}

==External links==
*[http://www.minorplanetcenter.org/iau/NatSats/NaturalSatellites.html IAU-MPC NSES]
*[https://web.archive.org/web/20071109115620/http://solarsystem.nasa.gov/planets/profile.cfm?Object=Jup_Ananke Ananke Profile] by [http://solarsystem.nasa.gov NASA's Solar System Exploration]
*[http://www2.ess.ucla.edu/~jewitt/irregulars.html David Jewitt pages]
*[https://web.archive.org/web/20021016114810/http://www.ifa.hawaii.edu/~sheppard/satellites/jupsatdata.html Scott Sheppard pages]

{{Moons of Jupiter}}

{{DEFAULTSORT:Ananke (Moon)}}
[[Category:Ananke group]]
[[Category:Moons of Jupiter]]
[[Category:Irregular satellites]]
[[Category:Astronomical objects discovered in 1951|19510928]]
[[Category:Discoveries by Seth B. Nicholson]]
[[Category:Moons with a retrograde orbit]]