Occator (crater)

Occator /ɒˈkeɪtər/ is an impact crater located on Ceres, the largest object in the main asteroid belt that lies between the orbits of Mars and Jupiter, that contains "Spot 5", the brightest of the bright spots observed by the Dawn spacecraft. It was known as "Region A" in ground-based images taken by the W. M. Keck Observatory on Mauna Kea.[2]

Further information: Bright spots on Ceres § Spot 5

Occator
Occator imaged by Dawn from LAMO. Fractures are associated with the bright spots and some other areas.
LocationCeres
Coordinates19.86°N 238.85°E / 19.86; 238.85[1]
Diameter92 kilometres (57 mi)
Depth4 km
NamingAfter Occātor, a helper God of Ceres

The crater was named after Occator, the Roman god of the harrow and a helper to Ceres. The name Occator was officially approved by the IAU on 3 July 2015.[1]

On 9 December 2015, scientists reported that the bright spots on Ceres, including those in Occator, may be related to a type of salt, particularly a form of brine containing magnesium sulfate hexahydrite (MgSO4·6H2O); the spots were also found to be associated with ammonia-rich clays.[3] More recently, on 29 June 2016, scientists reported the bright spot to be mostly sodium carbonate (Na
2CO
3), implying that hydrothermal activity was probably involved in creating the bright spots.[4][5] In August 2020, NASA confirmed that Ceres was a water-rich body with a deep reservoir of brine that percolated to the surface in various locations causing the "bright spots", including those in Occator crater.[6][7]

A small dome in the center of the crater is 3 km across and about 340 meters height. It is named Cerealia Tholus[8] and is covered by bright salt deposits named Cerealia Facula.[9] The group of thinner salt deposits to the east are named Vinalia Faculae [sic].[10] In July 2018, NASA released a comparison of physical features, including Occator, found on Ceres with similar ones present on Earth.[11]

Views
Highest-resolution mosaic of Cerealia Facula - click to see full image (Final orbit; July 2018)
(use large image viewer to avoid browser crashes)
Highest-resolution mosaic of the Vinalia Faculae - click to see full image (Final orbit; July 2018)
(use large image viewer to avoid browser crashes)
Context - Center of Occator (enhanced color; LAMO; February 2016)
Bright spot may be mostly sodium carbonate (NASA; June 2016).[4]
Ceres - crater Occator - simulated perspectives
Looking north
Looking south
NASA (December 2017)
Final orbit - Cerealia Facula - Mosaic Topography Model
(22 km (14 mi)) (August 2018)
Last view from Dawn (1 November 2018)[12][13][14]
  • View rendered from
    topographic data
  • Topographic map
    (October 2015)
  • Occator from HAMO. Composite image, so bright spot is not overexposed.
  • Oblique view
    (October 2015)
  • Lateral view
  • Lateral view
    (December 2015)
  • False colors
    (December 2015)
  • 3D-like perspective
    (December 2015)
  • Western rim
    (January 2016)
  • Southeastern rim
    (January 2016)
  • Fractures inside crater
    (August 2016)
  • LAMO close-up
    CerealiaFacula
    (February 2016)
  • Context of preceding image
    (LAMO; March 2016)
  • Final orbit-FloorFractures
    (116 km (72 mi))
    (July 2018)
  • Final orbit-FractureNetwork
    (107 km (66 mi))
    (July 2018)
  • Final orbit-FractureNetwork
    (76 km (47 mi))
    (July 2018)
  • Final orbit-FractureNetwork
    (46 km (29 mi))
    (July 2018)
  • Final orbit-FractureNetwork
    (36 km (22 mi))
    (June 2018)
  • Final orbit-Fractures
    (35 km (22 mi))
    (July 2018)
  • Final orbit-Dome & Fractures
    (44 km (27 mi))
    (July 2018)
  • Final orbit-Dome
    (51 km (32 mi))
    (July 2018)
  • Final orbit-FloorPatterns
    (52 km (32 mi))
    (July 2018)
  • Final orbit-Floor
    (48 km (30 mi))
    (July 2018)
  • Final orbit-Scarp
    (42 km (26 mi))
    (July 2018)
  • Final orbit-Landslides
    (44 km (27 mi))
    (June 2018)
  • Final orbit-Boulders
    (43 km (27 mi))
    (June 2018)
  • Final orbit-CraterWall
    (116 km (72 mi))
    (July 2018)
  • Final orbit-CraterWall
    (116 km (72 mi))
    (July 2018)
  • Final orbit-EasternRim-1
    (44 km (27 mi))
    (June 2018)
  • Final orbit-EasternRim-2
    (44 km (27 mi))
    (June 2018)
  • Final orbit-NorthernWall
    (33 km (21 mi))
    (June 2018)
  • Final orbit-SoutheastWall
    (39 km (24 mi))
    (June 2018)
  • Final orbit-Stars
    (143 km (89 mi))
    (July 2018)
  • Final orbit-Stars
    (34 km (21 mi))
    (June 2018)
  • Final orbit-BrightMaterial
    (48 km (30 mi))
    (July 2018)
  • Final orbit-BrightMaterial
    (55 km (34 mi))
    (July 2018)
  • Final orbit-VinaliaFaculae
    (39 km (24 mi))
    (June 2018)
  • Final orbit-VinaliaFaculae
    (58 km (36 mi))
    (July 2018)
  • Context of preceding image
  • Final orbit-FracturePattern-NearCerealiaFacula
    (54 km (34 mi))
    (July 2018)
  • Final orbit-CerealiaFacula-a
    (34 km (21 mi))
    (June 2018)
  • Context of preceding image
  • Final orbit-CerealiaFacula-b
    (34 km (21 mi))
    (June 2018)
  • Final orbit-CerealiaFacula-c
    (34 km (21 mi))
    (June 2018)
  • Occator crater
    Bright Areas
    (10 August 2020)
  • Occator crater
    CloseUp
    (10 August 2020)

Animations
  • 4 February 2015; Dawn
    90,000 km (56,000 mi)
  • 29 April 2017: Dawn
    20,000 km (12,000 mi)
  • 4 May 2015; Dawn
    13,600 km (8,500 mi)
  • 4 May 2015; Dawn
    13,600 km (8,500 mi)
    bright spots
Ceres flyover animations
Surface features exaggerated
(simulated; 01:15; 8 June 2015)[15]
Focus on Occator
(false colors; 01:12; 9 December 2015)
Flight over dwarf planet Ceres
(color; 03:43; 29 January 2016)
Ceres – Occator crater – "bright areas" (animation; 10 August 2020

See also

References
  1. "Occator (crater)". Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program., accessed 6 July 2015
  2. Kupper; et al. (22 January 2014). "PIA17831: Water Detection on Ceres". NASA. Retrieved 30 July 2015.
  3. Landau, Elizabeth (9 December 2015). "New Clues to Ceres' Bright Spots and Origins". NASA. Retrieved 10 December 2015.
  4. Landau, Elizabeth; Greicius, Tony (29 June 2016). "Recent Hydrothermal Activity May Explain Ceres' Brightest Area". NASA. Retrieved 30 June 2016.
  5. De Sanctis, M. C.; Raponi, A.; Ammannito, E.; Ciarniello, M.; Toplis, M. J.; McSween, H. Y.; Castillo-Rogez, J. C.; Ehlmann, B. L.; Carrozzo, F. G.; Marchi, S.; Tosi, F.; Zambon, F.; Capaccioni, F.; Capria, M. T.; Fonte, S.; Formisano, M.; Frigeri, A.; Giardino, M.; Longobardo, A.; Magni, G.; Palomba, E.; McFadden, L. A.; Pieters, C. M.; Jaumann, R.; Schenk, P.; Mugnuolo, R.; Raymond, C. A.; Russell, C. T. (29 June 2016). "Bright carbonate deposits as evidence of aqueous alteration on (1) Ceres". Nature. 536 (7614): 54–57. Bibcode:2016Natur.536...54D. doi:10.1038/nature18290. PMID 27362221. S2CID 4465999.
  6. McCartney, Gretchen; JHautaluoma, Grey; Johnson, Alana (10 August 2020). "Mystery Solved: Bright Areas on Ceres Come From Salty Water Below". NASA. Retrieved 12 August 2020.
  7. McCartney, Gretchen (11 August 2020). "Mystery solved: Bright areas on Ceres come from salty water below". Phys.org. Retrieved 12 August 2020.
  9. "Cerealia Facula". Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program.
  10. "Vinalia Faculae". Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program.
  11. Landau, Elizabeth; McCartney, Gretchen (24 July 2018). "What Looks Like Ceres on Earth?". NASA. Retrieved 25 July 2018.
  12. Brown, Dwayne; Wendel, JoAnna; McCartney, Gretchen (6 September 2018). "The Legacy of NASA's Dawn, Near End of Mission". NASA. Retrieved 2 November 2018.
  13. Brown, Dwayne; Wendel, JoAnna; McCartney, Gretchen (1 November 2018). "NASA's Dawn Mission to Asteroid Belt Comes to End". NASA. Retrieved 2 November 2018.
  14. Chang, Kenneth (1 November 2018). "NASA's Dawn Mission to the Asteroid Belt Says Good Night - Launched in 2007, the spacecraft discovered bright spots on Ceres and forbidding terrain on Vesta". The New York Times. Retrieved 2 November 2018.
  15. Landau, Elizabeth; Dyches, Preston (8 June 2015). "Fly Over Ceres in New Video". NASA. Retrieved 9 June 2015.
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