Ananke (moon)
| Ananke | |
|---|---|
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| Ananke on August 15, 1998 at 00:47 UTC from the OHP (Observatoire de Haute-Provence) with a 120-centimeter telescope | |
| Provisional or systematic name | Jupiter XII |
| Central body | Jupiter |
| Properties of the orbit | |
| Major semi-axis | 21,276,000 km |
| Periapsis | 16,095,000 km |
| Apoapsis | 26,457,000 km |
| eccentricity | 0.2435 |
| Orbit inclination | 148.89 °° |
| Orbital time | 629,770 d |
| Mean orbital velocity | 2.42 km / s |
| Physical Properties | |
| Albedo | 0.04 |
| Apparent brightness | 18.75 likes |
| Medium diameter | 28.0 km |
| Dimensions | 3.0 x 10 16 kg |
| surface | 2,463 km 2 |
| Medium density | 2.6 g / cm 3 |
| Acceleration of gravity on the surface | ≈ 0.010 m / s 2 |
| Escape speed | ≈ 16.9 m / s |
| discovery | |
| Explorer | |
| Date of discovery | September 28, 1951 |
Ananke (also Jupiter XII ) is one of the outer moons of the planet Jupiter .
discovery
Ananke was discovered on September 28, 1951 by the astronomer Seth Barnes Nicholson at the Mount Wilson Observatory in California .
The moon was named after Ananke , a lover of Zeus from Greek mythology . It received its official name in 1975. Previously it was referred to as Jupiter's moon XII , as it was the twelfth discovered moon on the planet.
Orbit data
Ananke orbits Jupiter at an average distance of 21.28 million km in 629 days, 18 hours and 29 minutes. The track has an eccentricity of 0.2435. With an inclination of 148.9 ° to the local Laplace plane , the orbit is retrograde , that is, the moon moves around the planet against the direction of rotation of Jupiter.
Ananke is the namesake of a group of moons that move on similar orbits around Jupiter. The Ananke group comprises eight to sixteen moons, with Ananke being the largest member.
Physical data
Ananke has a mean diameter of about 28 km. Their density is estimated at 2.6 g / cm³. It is probably made up mainly of silicate rock. Ananke has a very dark surface with an albedo of 0.04. Their apparent brightness is 18.8 m .
Remarks
- ↑ The Laplace Plain of Ananke deviates quite clearly from the ecliptic for an outer moon with about 2.4 ° . The reason for this are external disturbances , especially from the large neighboring planet Saturn . The Laplace plane is inclined by about 4.9 ° to the equatorial plane of Jupiter.
Web links
- Seth B. Nicholson, "An Unidentified Object Near Jupiter, Probably a New Satellite", in: Publications of the Astronomical Society of the Pacific , Vol. 63 (1951), No. 375, p. 297-299. (Discovery)
- IAUC 2846: Satellites of Jupiter October 7, 1975 (designation)
- https://solarsystem.nasa.gov/planets/ananke/facts
- https://planetarynames.wr.usgs.gov/Page/Planets
Individual evidence
- ^ A b R. A. Jacobson: The Orbits of Outer Jovian Satellites . In: Astronomical Journal . 120, 2000, pp. 2679-2686. doi : 10.1086 / 316817 .
| before | Jupiter moons | after that |
| Carme | Ananke |
Leda |