Anthe (moon)
Cassini Imaging Science Team
Anthe ( Saturn XLIX ) is the twelfth and one of the smallest of the 62 known moons of the planet Saturn. Your orbit lies between those of the large moons Mimas and Enceladus and the moons of this section, which also includes Methoni and Pallene include the Alkyoniden group are called.
Discovery
The discovery of Anthe by the Cassini Imaging Science Team on recordings of 30 May 2007 and earlier recordings, which date back to June 2004, was announced on 18 July 2007. Anthe is the 60th confirmed moon of Saturn system.
Anthe first received the provisional designation S/2007 S 4, and was named by its discoverers unofficially Frank. In August 2007, the moon was named after one of the seven daughters of the giants Alkyoneus from Greek mythology ( Alkyoniden ). Alkyoneus was a son of Gaia and the blood of Uranus. The giant came in giants fight by Heracles killed. Methoni and her six sisters ( including Methoni and Pallene ) were about the death of his father in mourning so that they threw themselves into the sea down from kanasträischen foothills. But out of pity saved them the Oceanid (or Nereid ) Amphitrite life and turned them into kingfishers.
Web properties
Orbit
Anthe orbiting Saturn on a prograde, nearly perfectly circular orbit at an average distance of 197,700 kilometers (about 3,280 Saturn radii ) from the center, or about 137,430 km on whose cloud tops. The orbital eccentricity is 0.0011, the orbit is inclined 0.1 ° relative to the equator of Saturn, that is nearly in the equatorial plane of the planet. Due to the low eccentricity of the track varies in distance to Saturn at about 400 km.
The orbit of the next inner moon Methoni is located on average about 3260 km from the orbit of Anthe, the distance of the path of the next outer moon Pallene averages about 14.6 thousand kilometers.
Anthe orbits Saturn in 1 day, 0 hours, 52 minutes and 33.6 seconds. You need for a round 38.8 minutes longer than the inner neighboring Methoni. She puts in 24 hours a distance of 347 °.
Anthe is located in a 10:11 orbital resonance with the moon Mimas inward current. This orbit of Mimas is heavily disturbed. The much more massive Mimas caused by its gravitational variations in Methoni train of about 200 km. The influence of the orbital resonance also to the fact that in Methoni 14 ° longitude in its orbit moves back and forth leads.
Anthe Ring Arc
Despite the small size of Anthe was discovered a ring system in June 2007, before and after this. However, this is not a closed system around Saturn, but it extends only a few thousand kilometers before and behind Methoni and migrates with the latter. It is believed that the ring arcs from Anthe and Methoni probably evolved from material that has been hit by micrometeorites from these two moons. Due to the gravitational resonance with Mimas they are held by the latter in their form; Mimas prevented so that the ring material is distributed as with the other rings of Saturn around the web and forms a uniform ring.
Physical Properties
Anthe has a diameter of about 1.8 km. At an average density of 0.5 g/cm3 results in a mass of 1.4987 · 1012 kg. On its surface, the acceleration due to gravity is 0.00012 m/s2, this corresponds to only about 0.01 ‰ of the earth.
So far, there are two theories on the development of three closely spaced Monde Methoni, Anthe and Pallene: First, they were broken by either Mimas or Enceladus by a collision with a comet or asteroid, on the other hand, could all these five moons even be residues of a larger swarm, has migrated into this region close to Saturn.
Research
Anthe has an apparent magnitude of 26.0 m, which is 1:13000000000 of the central planet. Methoni was attended by four space probes so far, from the flyby probe Pioneer 11 on 1 September 1979, Voyager 1 on 12 November 1980 and Voyager 2 on August 25, 1981 ( these were made without any sighting of the moon ), and finally Cassini-Huygens.
Since the discovery in 2007 of their orbital parameters could by the Cassini spacecraft in orbit around Saturn since July 1, 2004, to be precise.