Odysseus is the largest crater on Saturn's moonTethys. It is 445 km across, more than 2/5 of the moon's diameter, and is one of the largest craters in the Solar System. It is situated in the western part of the leading hemisphere of the moon—the latitude and longitude of its center are 32.8°N and 128.9°W, respectively. It is named after the Greek hero Odysseus from Homer's the Iliad and the Odyssey.[1] Odysseus was discovered by the Voyager 2 spacecraft on 1 September 1981 during its flyby of Saturn.[2]
Inktomi
Tethys, with Odysseus at the top, as imaged by Cassini on February 14, 2010
Enhanced-color map (left) and elevation map (right). In the elevation map, dark blue represents lower elevations and red represents higher elevations
The Odysseus crater is now quite flat for its size of approximately 450 km or more precisely, its floor conforms to Tethys' spherical shape. This is most likely due to the viscous relaxation of the Tethyan icy crust over geologic time. The floor lies approximately 3 km below the mean radius, while its exterior rim is about 5 km above the mean radius—the relief of 6–9 km is not very high for such a large crater. Inside the crater the rim is composed of arcuate scarps and extends for about 100 km until the floor is reached. There are several graben radiating away from Odysseus, which are 10–20 km wide and hundreds of kilometers long. They are likely to be cracks in the crust created by the impact.[3] The most prominent among them is called Ogygia Chasma.[4]
The crater must have originally been deep, with a high mountainous rim and towering central peak. Over time the crater floor has relaxed to the spherical shape of the Tethyan surface, and the crater's rim and central peak have collapsed (similar relaxation is apparent on Jupiter's moons Callisto and Ganymede). This indicates that at the time of the Odysseus impact, Tethys must have been sufficiently warm and malleable to allow the topography to collapse; its interior may have even been liquid. If Tethys had been colder and more brittle at the time of impact, the moon might have been shattered, and even if it survived the impact, the topography of the crater would have retained its shape, similarly to the crater Herschel on Mimas.[5][6]: 642
The central complex of Odysseus (Scheria Montes)[7] features a central pit-like depression,[6]: 642 which is 2–4 km deep. It is surrounded by massifs elevated by 2–3 km above the crater floor, which itself is about 3 km below the average radius.[3]
Relation to Ithaca Chasmaedit
The immense trench called Ithaca Chasma, which approximately follows a great circle with a pole near Odysseus' center, had been hypothesized to have formed as a result of the Odysseus impact.[3] However, a study based on high resolution Cassini images indicated that this is unlikely—the crater counts inside Odysseus appear to be lower than in Ithaca Chasma, indicating that the latter is older than the former.[8][6]: 669
^ abc"Odysseus". Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program. (Center Latitude: 32.82°, Center Longitude: 128.89°)
^Stone, E. C.; Miner, E. D. (29 January 1982). "Voyager 2 Encounter with the Saturnian System" (PDF). Science. 215 (4532): 499–504. Bibcode:1982Sci...215..499S. doi:10.1126/science.215.4532.499. PMID 17771272. S2CID 33642529.
^ abcMoore, Jeffrey M.; Schenk, Paul M.; Bruesch, Lindsey S.; Asphaug, Erik; McKinnon, William B. (October 2004). "Large impact features on middle-sized icy satellites" (PDF). Icarus. 171 (2): 421–443. Bibcode:2004Icar..171..421M. doi:10.1016/j.icarus.2004.05.009.
^"Tethys: Ogygia Chasma". Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program.
^Hamilton, Calvin J. (19 February 1999). "Odysseus Basin on Saturn's Moon Tethys". SolarViews.com. SolarViews. Retrieved 19 December 2011.
^ abcJaumann, R.; Clark, R. N.; Nimmo, F.; Hendrix, A. R.; Buratti, B. J.; Denk, T.; Moore, J. M.; Schenk, P. M.; Ostro, S. J.; Srama, Ralf (2009). "Icy Satellites: Geological Evolution and Surface Processes". Saturn from Cassini-Huygens. pp. 637–681. doi:10.1007/978-1-4020-9217-6_20. ISBN978-1-4020-9216-9.
^"Tethys: Scheria Montes". Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program.
^Giese, B.; Wagner, R.; Neukum, G.; Helfenstein, P.; Thomas, P. C. (2007). "Tethys: Lithospheric thickness and heat flux from flexurally supported topography at Ithaca Chasma" (PDF). Geophysical Research Letters. 34 (21): 21203. Bibcode:2007GeoRL..3421203G. doi:10.1029/2007GL031467.
External linksedit
NASA Astronomy Picture of the Day: The Great Basin on Tethys (8 February 2006)
NASA Astronomy Picture of the Day: Odysseus Crater on Tethys (5 February 2017)
January 01, 1970
odysseus, crater, odysseus, largest, crater, saturn, moon, tethys, across, more, than, moon, diameter, largest, craters, solar, system, situated, western, part, leading, hemisphere, moon, latitude, longitude, center, respectively, named, after, greek, hero, od. Odysseus is the largest crater on Saturn s moon Tethys It is 445 km across more than 2 5 of the moon s diameter and is one of the largest craters in the Solar System It is situated in the western part of the leading hemisphere of the moon the latitude and longitude of its center are 32 8 N and 128 9 W respectively It is named after the Greek hero Odysseus from Homer s the Iliad and the Odyssey 1 Odysseus was discovered by the Voyager 2 spacecraft on 1 September 1981 during its flyby of Saturn 2 InktomiTethys with Odysseus at the top as imaged by Cassini on February 14 2010Feature typeCentral peak impact craterLocationTethysCoordinates32 49 N 128 53 W 32 82 N 128 89 W 32 82 128 89 1 Diameter445 km 277 mi 1 EponymOdysseus Contents 1 Geology 1 1 Relation to Ithaca Chasma 2 See also 3 References 4 External linksGeology edit nbsp Enhanced color map left and elevation map right In the elevation map dark blue represents lower elevations and red represents higher elevations The Odysseus crater is now quite flat for its size of approximately 450 km or more precisely its floor conforms to Tethys spherical shape This is most likely due to the viscous relaxation of the Tethyan icy crust over geologic time The floor lies approximately 3 km below the mean radius while its exterior rim is about 5 km above the mean radius the relief of 6 9 km is not very high for such a large crater Inside the crater the rim is composed of arcuate scarps and extends for about 100 km until the floor is reached There are several graben radiating away from Odysseus which are 10 20 km wide and hundreds of kilometers long They are likely to be cracks in the crust created by the impact 3 The most prominent among them is called Ogygia Chasma 4 The crater must have originally been deep with a high mountainous rim and towering central peak Over time the crater floor has relaxed to the spherical shape of the Tethyan surface and the crater s rim and central peak have collapsed similar relaxation is apparent on Jupiter s moons Callisto and Ganymede This indicates that at the time of the Odysseus impact Tethys must have been sufficiently warm and malleable to allow the topography to collapse its interior may have even been liquid If Tethys had been colder and more brittle at the time of impact the moon might have been shattered and even if it survived the impact the topography of the crater would have retained its shape similarly to the crater Herschel on Mimas 5 6 642 The central complex of Odysseus Scheria Montes 7 features a central pit like depression 6 642 which is 2 4 km deep It is surrounded by massifs elevated by 2 3 km above the crater floor which itself is about 3 km below the average radius 3 Relation to Ithaca Chasma edit The immense trench called Ithaca Chasma which approximately follows a great circle with a pole near Odysseus center had been hypothesized to have formed as a result of the Odysseus impact 3 However a study based on high resolution Cassini images indicated that this is unlikely the crater counts inside Odysseus appear to be lower than in Ithaca Chasma indicating that the latter is older than the former 8 6 669 See also editTirawa A similar impact basin on RheaReferences edit a b c Odysseus Gazetteer of Planetary Nomenclature USGS Astrogeology Research Program Center Latitude 32 82 Center Longitude 128 89 Stone E C Miner E D 29 January 1982 Voyager 2 Encounter with the Saturnian System PDF Science 215 4532 499 504 Bibcode 1982Sci 215 499S doi 10 1126 science 215 4532 499 PMID 17771272 S2CID 33642529 a b c Moore Jeffrey M Schenk Paul M Bruesch Lindsey S Asphaug Erik McKinnon William B October 2004 Large impact features on middle sized icy satellites PDF Icarus 171 2 421 443 Bibcode 2004Icar 171 421M doi 10 1016 j icarus 2004 05 009 Tethys Ogygia Chasma Gazetteer of Planetary Nomenclature USGS Astrogeology Research Program Hamilton Calvin J 19 February 1999 Odysseus Basin on Saturn s Moon Tethys SolarViews com SolarViews Retrieved 19 December 2011 a b c Jaumann R Clark R N Nimmo F Hendrix A R Buratti B J Denk T Moore J M Schenk P M Ostro S J Srama Ralf 2009 Icy Satellites Geological Evolution and Surface Processes Saturn from Cassini Huygens pp 637 681 doi 10 1007 978 1 4020 9217 6 20 ISBN 978 1 4020 9216 9 Tethys Scheria Montes Gazetteer of Planetary Nomenclature USGS Astrogeology Research Program Giese B Wagner R Neukum G Helfenstein P Thomas P C 2007 Tethys Lithospheric thickness and heat flux from flexurally supported topography at Ithaca Chasma PDF Geophysical Research Letters 34 21 21203 Bibcode 2007GeoRL 3421203G doi 10 1029 2007GL031467 External links editNASA Astronomy Picture of the Day The Great Basin on Tethys 8 February 2006 Astronomy Picture of the Day for 9 September 2007 NASA Astronomy Picture of the Day Odysseus Crater on Tethys 5 February 2017 Retrieved from https en wikipedia org w index php title Odysseus crater amp oldid 1223261676, wikipedia, wiki, book, books, library,
