Anthe (moon)
 Anthe as imaged by the Cassini orbiter in January 2016 | |
| Discovery | |
|---|---|
| Discovered by | Cassini Imaging Team [1] |
| Discovery date | May 30, 2007 |
| Designations | |
Designation | Saturn XLIX |
| Pronunciation | /ˈænθiː/[a] |
Named after | Άνθη Anthē |
| Adjectives | Anthean /ænˈθiːən/ |
| Orbital characteristics[2] | |
| Epoch 2007 May 30 04:02:02.511 UTC (JED 2454250.66883907) | |
| 197655±26 km | |
| Eccentricity | 0.0012±0.0008 |
| 1.036517 d[3] | |
Average orbital speed | 13.824 km/s[4] |
| Inclination | 0.017°±0.004° (to Saturn's equator) |
| Satellite of | Saturn |
| Physical characteristics | |
| 0.75–2.4 km[5] | |
Mean density | 0.5 g/cm3 (assumed)[6] |
| assumed synchronous | |
| assumed zero | |
| Albedo | 0.25–1 (geometric)[5] |
Anthe /ˈænθiː/ is a very small natural satellite of Saturn lying between the orbits of Mimas and Enceladus. It is also known as Saturn XLIX; its provisional designation was S/2007 S 4. It is named after one of the Alkyonides; the name means flowery. It is the sixtieth confirmed moon of Saturn.[7]
The designation S/2007 S 4 was also accidentally and incorrectly used for a different Saturnian satellite discovered later. The published discovery was retracted a few hours later and republished the next day under the correct name of S/2007 S 5.
Discovery
[edit source]It was discovered by the Cassini Imaging Team[1] in images taken on 30 May 2007.[4] Once the discovery was made, a search of older Cassini images revealed it in observations from as far back as June 2004. It was first announced on 18 July 2007.[4]
Characteristics
[edit source]
Anthe is visibly affected by a perturbing 10:11 mean-longitude resonance with the much larger Mimas. This causes its osculating orbital elements to vary with an amplitude of about 20 km in semi-major axis on a timescale of about 2 Earth years. The close proximity to the orbits of Pallene and Methone suggests that these moons may form a dynamical family.[citation needed]
The ratio of Anthe's medium axis to its long axis is ≈0.7, and the ratio of its short axis to its medium axis is ≈0.95. This implies that it has a similar shape to Methone.[8]
Material blasted off Anthe by micrometeoroid impacts is thought to be the source of the Anthe Ring Arc, a faint partial ring about Saturn co-orbital with the moon first detected in June 2007.[9][10]
References
[edit source]Notes
[edit source]Citations
[edit source]- 1 2 Cassini Imaging Team.
- ↑ Cooper et al. 2008.
- ↑ Ciarniello et al. 2024.
- 1 2 3 IAUC 8857.
- 1 2 Thomas et al. 2013.
- ↑ Thomas & Helfenstein 2020.
- ↑ Agle 2007.
- ↑ Hedman, M. M.; Helfenstein, P.; Chancia, R. O.; Thomas, P.; Roussos, E.; Paranicas, C.; Verbiscer, A. J.; et al. (April 2020). "Photometric Analyses of Saturn's Small Moons: Aegaeon, Methone, and Pallene Are Dark; Helene and Calypso Are Bright". The Astronomical Journal. 159 (4): 48. arXiv:1912.09192. Bibcode:2020AJ....159..129H. doi:10.3847/1538-3881/ab659d. S2CID 209414585. 129.
- ↑ Porco et al., 2008.
- ↑ Hedman et al., 2009.
Sources
[edit source]- "Cassini Imaging Science Team". Cassini Imaging Central Laboratory for OPerationS. Archived from the original on 2011-05-20. Retrieved 2012-01-01.
- Agle, D. C. (July 19, 2007). "Saturn Turns 60". Cassini Solstice Mission. JPL/NASA. Archived from the original on February 20, 2012. Retrieved 2012-01-01.
- Green, Daniel W. E. (July 18, 2007). "S/ 2007 S 4". IAU Circular. 8857. Retrieved 2012-01-01.
- Cooper, N. J.; Murray, C. D.; Evans, M. W.; Beurle, K.; Jacobson, R. A.; Porco, C. C. (2008-06-01). "Astrometry and dynamics of Anthe (S/2007 S 4), a new satellite of Saturn". Icarus. 195 (2): 765–777. Bibcode:2008Icar..195..765C. doi:10.1016/j.icarus.2008.01.006. ISSN 0019-1035.
- Hedman, M. M.; Murray, C. D.; Cooper, N. J.; Tiscareno, M. S.; Beurle, K.; Evans, M. W.; Burns, J. A. (2008-11-25). "Three tenuous rings/arcs for three tiny moons". Icarus. 199 (2): 378–386. Bibcode:2009Icar..199..378H. doi:10.1016/j.icarus.2008.11.001. ISSN 0019-1035.
- Porco C. C.; et al. (2008-09-05). "More Ring Arcs for Saturn". Cassini Imaging Central Laboratory for Operations. Archived from the original on 2008-10-10. Retrieved 2008-09-05.
- Thomas, P. C.; Burns, J. A.; Hedman, M.; Helfenstein, P.; Morrison, S.; Tiscareno, M. S.; Veverka, J. (2013-09-01). "The inner small satellites of Saturn: A variety of worlds". Icarus. 226 (1): 999–1019. doi:10.1016/j.icarus.2013.07.022. ISSN 0019-1035.
- Thomas, P. C.; Helfenstein, P. (July 2020). "The small inner satellites of Saturn: Shapes, structures and some implications". Icarus. 344: 20. Bibcode:2020Icar..34413355T. doi:10.1016/j.icarus.2019.06.016. S2CID 197474587. 113355.
- Ciarniello, Mauro; Filacchione, Gianrico; Nicholson, Philip D.; Hedman, Matthew M.; Charnoz, Sebastien; Cuzzi, Jeffrey N.; El Moutamid, Maryame; Hendrix, Amanda R.; Rambaux, Nicolas; Miller, Kelly E.; Mousis, Olivier; Baillié, Kevin; Estrada, Paul R.; Waite, J. Hunter (2024-09-17). "The Origin and Composition of Saturn's Ring Moons". Space Science Reviews. 220 (7): 72. doi:10.1007/s11214-024-01103-z. ISSN 1572-9672.
External links
[edit source]
Media related to Anthe at Wikimedia Commons
- From Dark Obscurity... A Tiny New Saturnian Moon Comes To Light Archived 2011-02-02 at the Wayback Machine
Listed in approximate increasing distance from Saturn | |||||||||
| Inner ring moons |
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| Co-orbitals | |||||||||
| Ring-embedded moons | |||||||||
| Major moons (with trojans) | |||||||||
| Inuit group (39) |
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| Gallic group (19) | |||||||||
| Norse group (210) |
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| See also | |||||||||
| Geography |  | |
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| Moons | ||
| Astronomy | ||
| Exploration | ||
| Related | ||
