Aegaeon (moon)

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Three images of the bright arc of the G Ring with Aegaeon embedded within it, taken over the course of ten minutes

Aegaeon (/ˈən/ ee-JEE-ən; or as Greek Αιγαίων), also Saturn LIII (provisional designation S/2008 S 1), is a natural satellite of Saturn. Its discovery was announced by Carolyn Porco of the Cassini Imaging Science Team on March 3, 2009, from observations taken on August 15, 2008.[1]

Aegaeon orbits within the bright segment of Saturn's G Ring, and is probably a major source of the ring.[2] Debris knocked off the moon forms a bright arc near the inner edge, which in turn spreads to form the rest of the ring. Aegaeon orbits in a 7:6 resonance with Mimas, which causes a ≈ 4-year oscillation of ≈ 4 km in its semi-major axis. Assuming it has the same albedo as Pallene, it is estimated to be half a kilometer in diameter. It orbits Saturn at an average distance of 167,500 km in 0.80812 days, at an inclination of 0.001° to Saturn's equator, with an eccentricity of 0.0002.

It is named after Ægæon, one of the hecatonchires.[3]


  1. ^ IAU Circular No. 9023
  2. ^ Petite Moon, CICLOPS, 29 May 2009
  3. ^ Jennifer Blue, Saturnian Satellite Named Aegaeon, USGS Astrogeology Hot Topics, 5 May 2009