Ananke group

The Ananke group is a group of moons of Jupiter. They are retrograde non-spherical moons that follow similar orbits to Ananke and may have a common origin.

Their semi-major axes (distances from Jupiter) range between 19,300,000 and 22,700,000 km, their inclinations between 145.7° and 154.8°, and their orbital eccentricities between 0.02 and 0.28.

The core members include (from biggest to smallest):Scott S. Sheppard, David C. Jewitt, Carolyn Porco  
Jupiter's outer satellites and Trojans, 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, , 2004, p. 263 - 280
Full text(pdf).David Nesvorný, Cristian Beaugé, and Luke Dones
Collisional Origin of Families of Irregular Satellites, The Astronomical Journal, 127 (2004), pp. 1768–1783 Full text.
Ananke
Praxidike
Iocaste
Harpalyke
Thyone
Euanthe
Euporie
Hermippe
The International Astronomical Union (IAU) reserves names ending in -e for all retrograde moons, including this group's members.

Origin
The Ananke group is believed to have been formed when an asteroid was captured by Jupiter and broken apart by a collision.

Based on the sizes of the moons, the original asteroid may have been about 28 km in diameter. Since this value is near the approximate diameter of Ananke itself, it is likely the parent body was not heavily disrupted.(pdf).

Three of the moons of the family (Harpalyke, Praxidike and Iocaste) display similar grey colours while Ananke itself is on the boundary between grey and light red.Grav, Tommy; Holman, Matthew J.; Gladman, Brett J.; Aksnes, Kaare
Photometric survey of the irregular satellites,Icarus, 166,(2003), pp. 33-45. Preprint


References

Category:Jupiter's moons