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Jupiter VII

The second largest of a group of moons that orbit Jupiter beyond the Galilean Moons at a distance of nearly 12 million kilometres from the giant planet. This group, known as the Himalia group after by far its largest member, is thought to have originated as an asteroid, captured and sheared apart by Jupiter's gravity. Himalia represents the bulk of the debris of this shattered asteroid, with Elara as the largest of the remaining shards. The other smaller members of the group are the moons Leda, Lysithea, and possibly also the tiny moon Dia.

Elara itself is a dark body, some 86km in diameter and therefore probably rather irregular in shape. It turns on its axis every twelve hours, and currently completes an orbit of Jupiter every 260 days. All of the members of this group are highly affected by Jupiter's immense gravity, and this means that the characteristics of their eccentric orbits tend to change over time (indeed, it is possible that Elara has actually collided with other members of the group in the distant past).


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