Aegaeon (moon)

Cassini Imaging Science Team

Aegaeon ( Saturn LIII) is the ninth and one of the smallest inner of the 62 known moons of the planet Saturn. He is the only previously known moon of Saturn's G- ring of Saturn's rings.

  • 3.1 size
  • 3.2 Internal structure

Discovery and designation

Aegaeon was discovered on 15 August 2008 on two recordings of the Cassini spacecraft during a 600 -day specific observation of the G- ring by the Imaging Science Team of the Cassini mission. The G- ring ( → below ) was the only known outer ring of Saturn, was not having any of it dining moon known. The discovery was made on these first -mentioned recordings from August 15, 2008, and later the moon appeared on numerous recordings from 15 June 2007 to 20 February 2009.

The discovery was announced on March 3, 2009 by Carolyn C. Porco known, the director of the Imaging Science Team of the Cassini mission; the moon was in accordance with the Nomenclature of the International Astronomical Union ( IAU) the provisional designation S/2008 S initially 1

With Aegaeon the smallest at that time and the date of last 53 Saturn moons ( LIII) was named.

In May 2009, he was then after Hekatonchires Briareos (also called Aigaion ) named from Greek mythology, not to be confused with the sea god Aigaion, the son of Gaia and of the Pontos. In Homer Aigaion appears as the father of Briareos, after Virgil and Ovis as Briareos ( Aigaion ) itself Hekatonchires The three were 50-strong 100 -armed beings who made ​​a decisive contribution to the victory of the Olympian gods over the Titans in the titanic struggle. They were banished from their father Uranus, the hated her from the beginning, in the Erebus, and then the Mother Gaia incited the Titans to castrate their father with a flint sickle which Cronos (Roman equivalent Saturnus ) is the only Titan also did. Zeus and his siblings fought against the Titans for ten years and succeeded only after the liberation of Hekatonchires by Zeus to defeat the Titans, by this ( Briareos, and Gyges Kottos ) 300 piled rocks over the Titans. The vanquished were bound and banished to Tartarus, the Hekatonchires but were ordered to their guards. Briareos also received from the hand of his daughter Kymopolea Poseidon, who bore him the nymph Oiolyke.

The mentioned in Homer Aigaion as the father of Briareos was called by the gods so, but people should call him Aigaion because he rage the father of strength. When Hera, Poseidon and Athena conspired against Zeus, Thetis called the Briareos to Mount Olympus. Briareos was said to be so powerful that even the gods dared not oppose him.

In Callimachus, however Aigaion is a prisoner under the giant Etna, thus one of the enemy of Zeus in the giant battle.

The name comes from the god of the sea of the Aegean, Aigaion, the mighty son of Thalassa.

Web properties

Orbit

Aegaeon orbiting Saturn on a prograde, nearly perfectly circular orbit at an average distance of 167,500 kilometers (about 2,779 Saturn radii ) from the center, or about 107,230 km on whose cloud tops. The orbital eccentricity is 0.0002, the orbit is inclined 0.001 degrees from the equator of Saturn, that is almost exactly in the equatorial plane of the planet. Due to the low eccentricity of the track varies in distance from Saturn to only about 70 km.

The orbits of the co-orbital moons next inner Epimetheus and Janus are in the middle removed about 16,000 km from Aegaeons orbit, the distance of the path of the next outer moon Mimas averages about 17.9 thousand kilometers.

Aegaeon orbits Saturn in 19 hours, 23 minutes and 41.6 seconds. This lies between the orbital periods of Uranus moons Puck and Mab. Aegaeon needed for a round two hours and about 43.3 minutes longer than the inner neighbors Epimetheus and Janus.

Aegaeon is in a 7:6 orbital resonance with its outer - neighbor Mimas, which causes a pendulum motion of Aegaeons Large semi-major axis during an estimated period of 4 years for about four kilometers.

G- ring

The so-called G- ring, which stretches along the orbit of Aegaeon around Saturn, has a width of about 9,000 km. Centered on Aegaeon is a slightly lighter 250 km wide in comparison to the entire ring ring arc, which is comparable to the ring arcs in Neptune's Adams ring and expands and distributed by Aegaeon from about about 1/6 of the total volume of the G- ring. The ring arc seems to be down to a few meters in size, in contrast to the ubiquitous dust in the ring of ice particles and is fed by the impact of micrometeorites on Aegaeon, similarly as is the case with Enceladus and the E ring. Due to the variability of Aegaeon - web through the orbital resonance with Mimas and interaction with Saturn's magnetosphere is also distributed to the outside dust, since the plasma of the magnetosphere rotates faster than the G- ring. Thus, the ring loses over the millennia to ground and is refreshed by further strikes on Aegaeon.

Rotation

Aegaeons rotation period is not known, but it is likely that Aegaeon synchronously rotates and its axis has an inclination of about 0 °.

Physical Properties

Size

Aegaeon has a diameter of approximately 600 meters, such as when originating from the same albedo Pallene. He is presently the second smallest known ( and accepted ) and the smallest ever named Moon in Saturn as well as in the Solar System.

Internal construction

The mean density of Aegaeon is estimated with 0.50 g / cm ³ by far lower than that of the earth and even lower than the density of Saturn; she is so low that Aegaeon would float on water. This indicates that the moon is composed mainly of water ice. It is to assume that it belongs to the so-called Rubble Piles, which, due to the comparatively weak gravitational inside cavities.

Research

The small size and the low apparent magnitude of 27.0 m Aegaeon is hardly discernible by ground-based telescopes. Since he was not yet discovered at the time of flybys of the Voyager probes Voyager 1 and 2, missing data and images of these probes throughout.

It will take more shots of the Cassini spacecraft orbiting Saturn since July 1, 2004 and since the discovery in 2008 Aegaeon photographed several times to find out more about the moon experience.

Media

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