thumb|upright=1.5|This diagram compares the [[orbital elements and relative sizes of the known members of the Ananke group . The horizontal axis illustrates their average distance from Jupiter, the vertical axis their orbital inclination, and the circles their relative sizes.]]
thumb|upright=1.5|107 irregular moons of Jupiter plotted by semi-major axis and inclination . The Ananke group is shown as a tight cluster of yellow-colored points on the left.
The Ananke group (or family or cluster) is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Ananke and are thought to have a common origin.
Their semi-major axes (distances from Jupiter) range between 19.2 and 21.8 million km, their orbital inclinations between 144.3° and 155.5°, and their orbital eccentricities between 0.09 and 0.30.
The International Astronomical Union (IAU) reserves names ending in -e for all retrograde moons of Jupiter, including this group's members.
Origin
The Ananke group is believed to have been formed when an asteroid was captured by Jupiter and subsequently fragmented by a collision. This belief is founded on the fact that the dispersion of the mean orbital parameters of the core members is very small and can be accounted for by a small velocity impulse (15 < δV < 80 m/s), compatible with a single collision and breakup.
Available photometric studies put this in doubt, however, and suggest that secular resonance has mixed the Ananke and Pasiphae groups: three of the moons of the former family (Harpalyke, Praxidike and Iocaste) display similar grey colours (average colour indices: B−V = 0.77 and V−R = 0.42) while Ananke itself is on the boundary between grey and light red. At other times, there is no distinction made between the Ananke and Pasiphae groups, and the two may be considered a single group.
List
The members of the Ananke group are (in order of date announcement):