Anthe
| Anthe | |
 Anthe överst till vänster tillsammans med Methone nederst till höger, fotograferade av Cassini 29 oktober 2007 (NASA) | |
| Upptäckt | |
|---|---|
| Upptäckare | Cassini Imaging Science Team |
| Upptäcktsdatum | 30 maj 2007 |
| Uppkallad efter | Anthe |
| Omloppsbana | |
| Apoapsis | 197 900 km |
| Periapsis | 197 500 km |
| Halv storaxel | 197 700 km |
| Excentricitet | 0,001 |
| Siderisk omloppstid | 1,03650 dygn |
| Medelomloppshastighet | 13,86 km/s |
| Inklination | 0,1° |
| Måne till | Saturnus |
| Fysikaliska data | |
| Dimensioner | ≈ 1 km[1] |
| Massa | ≈ 5×1012 kg |
| Medeldensitet | 1,2 g/cm² (uppskattad) |
| Rotationsperiod | Troligen bunden rotation |
Anthe är en av Saturnus månar. Den gavs den tillfälliga beteckningen S/2007 S 4. Den betecknas också Saturn XLIX. Den upptäcktes av Cassini Imaging Science Team.[2] Upptäckten gjordes 30 maj 2007 men man har hittat fotografier av månen tagna redan 2004.[3] Namnet kommer från en av Alkyoneus döttrar inom grekisk mytologi.
Ringbågar
Trots Anthes ringa storlek upptäcktes i juni 2007 ett ringsystem som sträcker sig några kilometer före och efter Anthe. Ringsystemet är inte en komplett ring runt hela Saturnus.[4] En snarlik ringbåge finns i Methones omloppsbana.
Referenser
- ^ Saturnian Satellite Fact Sheet (NASA)
- ^ Planetary Satellite Discovery Circumstances, Jet Propulsion Laboratory, California Institute of Technology
- ^ International Astronomical Union Circulars 8857
- ^ Astronews (tyska)
Externa länkar
Wikimedia Commons har media som rör Anthe.
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Media som används på denna webbplats
Montage of Saturn and several of its satellites, Dione, Tethys, Mimas, Enceladus, Rhea, and Titan. JPL image PIA01482: Saturn System Montage This montage of images of the Saturnian system was prepared from an assemblage of images taken by the Voyager 1 spacecraft during its Saturn encounter in November 1980. This artist's view shows Dione in the forefront, Saturn rising behind, Tethys and Mimas fading in the distance to the right, Enceladus and Rhea off Saturn's rings to the left, and Titan in its distant orbit at the top.
Animated GIF of discovery images of Saturnian moon S/2007 S 4
Recent Cassini images show arcs of material co-orbiting with the Saturnian moons Anthe and Methone.
Arrows indicate the positions of Anthe, at top left, and Methone, at bottom right. Micrometeoroid impacts on the moons are the likely source of the arc material.
Cassini imaging scientists believe the process that maintains the Anthe and Methone arcs is similar to that which maintains the arc in the G ring (see Rounding the Corner). The general brightness of the image (along with the faint horizontal banding pattern) results from the long exposure time of 15 seconds required to capture the extremely faint ring arc and the processing needed to enhance its visibility (which also enhances the digital background noise in the image). The image was digitally processed to remove most of the background noise. This view looks toward the un-illuminated side of the rings from about 2 degrees above the ringplane.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Oct. 29, 2007. The view was acquired at a distance of approximately 2.3 million kilometers (1.4 million miles) from Anthe and 2.2 million kilometers (1.4 million miles) from Methone. Image scale is 14 kilometers (9 miles) per pixel on Anthe and 13 kilometers (8 miles) on Methone.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.
For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org .