Calypso (moon)
 Calypso image from Cassini (February 13, 2010) | |
| Discovery | |
|---|---|
| Discovered by |
|
| Discovery date | March 13, 1980 |
| Designations | |
Designation | Saturn XIV |
| Pronunciation | /kəˈlɪpsoʊ/[1] |
Named after | Καλυψώ Kalypsō |
| Tethys C S/1980 S 25 | |
| Adjectives | Calypsoan /kælɪpˈsoʊ.ən/,[2] Calypsonian /kælɪpˈsoʊniən/[3] |
| Orbital characteristics[4] | |
| 294670 km | |
| Eccentricity | 0.001 |
| 1.88780 d | |
| Inclination | 1.50° (to Saturn's equator) |
| Satellite of | Saturn |
| Physical characteristics | |
| Dimensions | 29.4 × 18.6 × 12.8 km (± 0.6 × 1.8 × 0.6 km)[5]: 2 |
| 19.0±0.8 km[5]: 2 | |
| Volume | 3591 km3[a] |
| Mass | ≈2.5×1015 kg[b] |
Mean density | ≈0.701 g/cm3[c] |
| ≈0.8–2.0 mm/s2[6]: 390 | |
| ≈ 0.005 km/s at longest axis to ≈ 0.007 km/s at poles | |
| synchronous[5]: 4 | |
| assumed zero | |
| Albedo | 1.34±0.10 (geometric)[7] |
Calypso is a natural satellite of Saturn. It was discovered in 1980, from ground-based observations, by Dan Pascu, P. Kenneth Seidelmann, William A. Baum, and Douglas G. Currie, and was provisionally designated S/1980 S 25 (the 25th satellite of Saturn discovered in 1980).[8] Several other apparitions of it were recorded in the following months: S/1980 S 29, S/1980 S 30,[9] S/1980 S 32,[10] and S/1981 S 2.[11] In 1983 it was officially named after Calypso of Greek mythology.[d] It is also designated Saturn XIV or Tethys C.
Calypso is co-orbital with the moon Tethys, and resides in Tethys's trailing Lagrangian point (L5), 60 degrees behind Tethys. This relationship was first identified by Seidelmann et al. in 1981.[12] The moon Telesto resides in the other (leading) Lagrangian point of Tethys, 60 degrees in the other direction from Tethys. Calypso and Telesto have been termed "Tethys trojans", by analogy to the trojan asteroids, and are half of the four presently known trojan moons.
Like many other small Saturnian moons and small asteroids, Calypso is irregularly shaped, has overlapping large craters, and appears to also have loose surface material capable of smoothing the craters' appearance. Its surface is one of the most reflective (at visual wavelengths) in the Solar System, with a visual geometric albedo of 1.34.[7] This very high albedo is the result of the sandblasting of particles from Saturn's E-ring, a faint ring composed of small, water-ice particles generated by Enceladus's south polar geysers.[13]
Gallery
[edit]
See also
[edit]References
[edit]Notes
[edit]- ↑ Calculated from Calypso's volume-equivalent sphere radius of 9.5±0.4 km given by Thomas et al. (2020)[5]: 2
- ↑ Calculated by multiplying Calypso's volume with its presumed density of 701 kg/m3.
- ↑ Density presumed from analyzing topographic features.[6]: 390
- ↑ Transactions of the International Astronomical Union, Vol. XVIIIA, 1982 (confirms Janus, names Epimetheus, Telesto, Calypso) (mentioned in IAUC 3872: Satellites of Jupiter and Saturn, September 30, 1983)
Citations
[edit]- ↑ "Calypso". Lexico UK English Dictionary. Oxford University Press. Archived from the original on 22 March 2020.
- ↑ The Emerson Society Quarterly, vol. 50, p. 56, 1968
- ↑ "Calypsonian". Lexico UK English Dictionary UK English Dictionary. Oxford University Press. Archived from the original on 22 March 2020.
- ↑ Ciarniello et al. 2024.
- 1 2 3 4 Thomas & Helfenstein 2020.
- 1 2 Thomas, Tiscareno & Helfenstein 2018.
- 1 2 Verbiscer French et al. 2007.
- ↑ IAUC 3496.
- ↑ IAUC 3549.
- ↑ IAUC 3605.
- ↑ IAUC 3593.
- ↑ Seidelmann Harrington et al. 1981.
- ↑ Mason 2010.
Sources
[edit]- Marsden, Brian G. (31 July 1980). "Satellites of Saturn" (discovery). IAU Circular (3496). Retrieved 23 December 2011.
- Marsden, Brian G. (11 December 1980). "Satellites of Saturn". IAU Circular (3549). Retrieved 23 December 2011.
- Marsden, Brian G. (16 April 1981). "Satellites of Saturn". IAU Circular (3593). Retrieved 23 December 2011.
- Marsden, Brian G. (18 May 1981). "Satellites of Saturn". IAU Circular (3605). Retrieved 23 December 2011.
- Marsden, Brian G. (30 September 1983). "Satellites of Jupiter and Saturn". IAU Circular (3872). Archived from the original on 25 July 2011. Retrieved 23 December 2011.
- Mason, Betsy (15 February 2010). "New Close-Ups of Saturn's Moons Mimas and Calypso". wired.com. Condé Nast Digital. Retrieved 23 December 2011.
- Seidelmann, P. K.; Harrington, R. S.; Pascu, D.; Baum, W. A.; Currie, D. G.; Westphal, J. A.; Danielson, G. E. (1981). "Saturn satellite observations and orbits from the 1980 ring plane crossing". Icarus. 47 (2): 282. Bibcode:1981Icar...47..282S. doi:10.1016/0019-1035(81)90172-X.
- Verbiscer, A.; French, R.; Showalter, M.; Helfenstein, P. (9 February 2007). "Enceladus: Cosmic Graffiti Artist Caught in the Act". Science. 315 (5813): 815. Bibcode:2007Sci...315..815V. doi:10.1126/science.1134681. PMID 17289992. S2CID 21932253. Retrieved 20 December 2011. (supporting online material, table S1)
- 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 (17 September 2024). "The Origin and Composition of Saturn's Ring Moons". Space Science Reviews. 220 (7): 72. Bibcode:2024SSRv..220...72C. doi:10.1007/s11214-024-01103-z. ISSN 1572-9672.
- Thomas, P.C.; Tiscareno, M.S.; Helfenstein, P. (2018). "The Inner Small Satellites of Saturn, and Hyperion". In Schenk, Paul M.; Clark, Roger Nelson; Howett, Carly J.A.; Verbiscer, Anne J.; Waite, John Hunter (eds.). Enceladus and the Icy Moons of Saturn. Space Science Series. Vol. 322. Tucson, AZ: The University of Arizona Press. pp. 387–408. Bibcode:2018eims.book..387T. doi:10.2458/azu_uapress_9780816537075-ch019. ISBN 978-0-8165-3707-5. JSTOR j.ctv65sw2b.36. LCCN 2017056126. OCLC 1055049948.
Further reading
[edit]- Thomas, P. C. (July 2010). "Sizes, shapes, and derived properties of the saturnian satellites after the Cassini nominal mission" (PDF). Icarus. 208 (1): 395–401. Bibcode:2010Icar..208..395T. doi:10.1016/j.icarus.2010.01.025. Archived from the original (PDF) on 23 December 2018. Retrieved 4 September 2015.
- Thomas, P. C.; Burns, J. A.; Hedman, M.; Helfenstein, P.; Morrison, S.; Tiscareno, M. S.; Veverka, J. (1 September 2013). "The inner small satellites of Saturn: A variety of worlds" (PDF). Icarus. 226 (1): 999–1019. Bibcode:2013Icar..226..999T. doi:10.1016/j.icarus.2013.07.022. ISSN 0019-1035. S2CID 33222737.
External links
[edit]
- "Calypso Profile". solarsystem.nasa.gov. Archived from the original on 20 November 2015.
- "Calypso". planetary.org. The Planetary Society. Archived from the original on 5 February 2012.
- Animation of photos from Cassini 2010-02-13 flyby on YouTube
- Raw images of Calypso from NASA
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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