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S/2003 J 12

S/2003 J 12 is a tiny moon, witb an estimated diameter of just one kilometre. This was the twelfth of numerous moons of Jupiter identified in the year 2003, hence its identifier (the moon has not yet been assigned a proper name). It orbits Jupiter at an average distance of nearly twenty-two million kilometres, following a somewhat eccentric orbital path that takes a total of 647 days to complete.

This orbit places it on the inner edge of the Ananke group, a family of related retrograde satellites of Jupiter orbiting far from the planet. This group are thought to have formed from the breakup of an asteroidal body captured by Jupiter's gravity, with the moon Ananke itself forming the largest remnant at nearly thirty kilometres across. The tiny S/2003 J 12 would therefore represent a much smaller shard of debris from the capture event that created this group of small satellites.