Seker (crater)

This article is about the crater on Ganymede. For the Egyptian god, see Sokar.
Seker
A Mercator projection image of Seker crater.
Feature typeBright halo dome crater
Coordinates39°10′S 345°23′W / 39.16°S 345.38°W / -39.16; -345.38
Diameter103 kilometres (64 mi)[1]
EponymSeker

Seker is a bright halo ray crater with a dome at its center on Jupiter's largest moon Ganymede. The crater is 103 kilometres (64 mi) wide.

Naming

Seker is named after an obscure hawk-headed god from Egyptian mythology who guarded the tombs in the city of Memphis, the ancient capital of Ancient Egypt.[2]

The name for Seker was approved in 1988 by the International Astronomical Union (IAU), the organization responsible for formally naming celestial bodies and their geological features,[1] following the convention that craters on Ganymede should be named after deities, heroes, and places from Middle Eastern mythology, including Egyptian mythology.[3]

Location

Seker is located in the southeast hemisphere of Ganymede. It lies near the boundary between the dark, ancient terrain known as Nicholson Regio and the younger, smoother terrain called Borsippa Sulcus.

The crater is within the Namtar quadrangle (or section) of Ganymede (designated Jg14).[4]

Seker crater lies on the hemisphere of Ganymede that permanently faces its parent planet, a consequence of the moon's synchronous rotation around Jupiter. Consequently, an observer standing at Seker would always see Jupiter in the sky.[a]

Age and Morphology

Seker is a crater with a bright floor and a dome at its center. It also exhibits broken rays, but most of them are very faint, likely because Seker is an ancient crater and its rays have largely been erased by space weathering.[6]

Seker's outer crater rim 103 kilometres (64 mi) wide, and it is one of Ganymede's dome craters.

Research suggests that Seker's central dome formed from meltwater produced beneath the crater when heat from the asteroid impact melted Ganymede's icy surface. As this meltwater refroze, it fractured and weakened the subsurface, causing the crater's center to collapse and form a circular pit resembling a sinkhole. Continued freezing led the meltwater to expand, uplifting the crater floor and ultimately creating an icy dome.[7] Such domes typically develop only in craters wider than 60 kilometres (37 mi).[8]

Exploration and Observation

As of 2026, the only spacecraft that has imaged Seker is Voyager 1, which did so during the probe's brief flyby of Ganymede and Jupiter in March 1979. It captured a single image of Seker and its surrounding terrain, which remains the only clear view of the crater to date.

During its orbit around Jupiter from December 1995 to September 2003, the Galileo space probe was not able to obtain close-up images of Seker crater. The probe only managed to image the crater during a distant flyby in September 1997.

Future missions

The European Space Agency's (ESA) flagship mission called the Jupiter Icy Moons Explorer (Juice) is scheduled to arrive at Jupiter in July 2031.[9] After spending approximately three and a half years in orbit around Jupiter and performing multiple flybys of Europa, Ganymede and Callisto, Juice will settle into a low orbit around Ganymede at a distance of as low as 500 kilometres (310 mi) in 2034.[10]

See also

Notes

  1. ^ For moons in synchronous rotation, such as Ganymede, 0° longitude corresponds to the part of the surface that always faces Jupiter. Regions between 90° W to 0° to 270° W longitude always face the moon’s parent planet.[5]

References

  1. ^ a b "GANYMEDE – Seker". USGS. 2015. Retrieved 2026-02-06.
  2. ^ "Egyptian Gods - The Complete List". World History Encyclopedia. 2016. Retrieved 2026-02-06.
  3. ^ "Categories (Themes) for Naming Features on Planets and Satellites". USGS. 2025. Retrieved 2026-01-06.
  4. ^ Ganymede Map Images Archived 2007-11-19 at the Wayback Machine
  5. ^ "Discussion of Chapter 6". Open University. Retrieved 2026-02-07.
  6. ^ Pieters, Carle; Noble, Sarah (2016-09-09). "Space weathering on airless bodies". AGU. 27 (5): 1867. doi:10.1002/2016JE005128. PMC 5975224. PMID 29862145.
  7. ^ Caussi, M. L.; Dombard, A. J.; Korycansky, D. G.; White, O. L.; Moore, J. M.; Schenk, P. M. (2024). "Dome Craters on Ganymede and Callisto May Form by Topographic Relaxation of Pit Craters Aided by Remnant Impact Heat". Journal of Geophysical Research: Planets. 129 (7) e2023JE008258. AGU Advance Earth and Space Science. arXiv:2403.15653. doi:10.1029/2023JE008258. Retrieved 2026-02-07.
  8. ^ "Unveiling the Origins of Dome Craters on Ganymede and Callisto". Eos / AGU Advance Earth and Space Science. 2024. Retrieved 2026-02-07.
  9. ^ "Juice Jupiter Icy Moons Explorer". ESA. 2023. Retrieved 2025-12-01.
  10. ^ "Juice's journey and Jupiter system tour". ESA. 2022. Retrieved 2025-12-01.
This article is issued from Wikipedia. The text is available under Creative Commons Attribution-Share Alike 4.0 unless otherwise noted. Additional terms may apply for the media files.