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This image shows the bright arc of Saturn's G ring that the moonlet Aegaeon orbits within. The moonlet is too small to be seen.
The image was taken in visible light by the Cassini spacecraft narrow-angle camera on the 24th January, 2010, when the spacecraft was approximately 1.7 million kilometres from Saturn.
The image scale is 10 kilometres per pixel.

Aegaeonb.jpg
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Credit:    NASA/JPL/Space Science Institute

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Title: Aegaeon (Saturn LIII), a G-ring object
Authors: M.M. Hedman, N.J. Cooper, C.D.Murray, K. Beurle, M.W. Evans, M.S. Tiscareno, J. A. Burns

Aegaeon (Saturn LIII, S/2008 S1) is a small satellite of Saturn that orbits within a bright arc of material near the inner edge of Saturn's G ring. This object was observed in 21 images with Cassini's Narrow-Angle Camera between June 15 (DOY 166), 2007 and February 20 (DOY 51), 2009. If Aegaeon has similar surface scattering properties as other nearby small Saturnian satellites (Pallene, Methone and Anthe), then its diameter is approximately 500 m. Orbit models based on numerical integrations of the full equations of motion show that Aegaeon's orbital motion is strongly influenced by multiple resonances with Mimas. In particular, like the G-ring arc it inhabits, Aegaeon is trapped in the 7:6 corotation eccentricity resonance with Mimas. Aegaeon, Anthe and Methone therefore form a distinctive class of objects in the Saturn system: small moons in co-rotation eccentricity resonances with Mimas associated with arcs of debris. Comparisons among these different ring-arc systems reveal that Aegaeon's orbit is closer to the exact resonance than Anthe's and Methone's orbits are. This could indicate that Aegaeon has undergone significant orbital evolution via its interactions with the other objects in its arc, which would be consistent with the evidence that Aegaeon's mass is much smaller relative to the total mass in its arc than Anthe's and Methone's masses are.

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