Anomalous Dome Crater

  • Henrik HargitaiEmail author
Living reference work entry
DOI: https://doi.org/10.1007/978-1-4614-9213-9_464-1

Category

Synonyms

Dome-type anomalous pit crater (Croft 1983); Large dome crater (Moore and Malin 1988); Type II penepalimpsest (Passey and Shoemaker 1982)

Description

Anomalous dome craters are 50–250 km diameter complex craters on the icy Galilean satellites. Anomalous dome craters exhibit a relatively bright, large circular dome, surrounded by a ring of rugged massifs. Surrounding this central complex is an annulus of smoothed or mottled material, the outer boundary of which is sometimes marked by a discontinuous circular lineament (Schenk 1996).

These craters differ from classical central dome craters in three respects:
  1. (1)

    Coherent rim structures are absent. They have a broad, low rise (Neith, Ganymede) (Fig. 1), incomplete outward or inward facing scarp segments (Doh, Callisto) (Fig. 2) or no observable rim (Anzu, Ganymede).

     
  2. (2)

    The dome-to-rim diameter ratio is roughly constant (0.4), regardless of crater size.

     
  3. (3)

    Anomalous dome craters are not associated with bright ray or floor deposits which suggests that they formed after bright materials were emplaced on Ganymede.

     
Fig. 1

Neith crater, Ganymede. Diameter is 165 km; dome diameter is 45 km. Galileo Orbit 7. PIA01648 (NASA/JPL/DLR)

Fig. 2

115-km-diameter Doh, Callisto, located in the central portion of Asgard multiring basin. Dome diameter is 25 km. North is down. Galileo 04133828.01 (NASA/JPL)

The lack of identifiable rim suggests a negligible crater depth (Schenk et al. 2004, p. 430).

Formation

Ejecta and secondary craters are recognized beyond their outer boundary, confirming an impact origin (central dome craters).

Studied Locations

Ganymede (e.g., Neith, Anzi) (Fig. 3), Callisto (e.g., Har, Doh)
Fig. 3

Anomalous dome craters and central pit craters near the limb of Ganymede. Voyager 2 mosaic (NASA/JPL/Ted Stryk)

See Also

Impact craters on icy moons with progressively decreasing relief:

Anomalous Dome Crater

Central Dome Crater

Palimpsest

Penepalimpsest

References

  1. Croft SK (1983) A proposed origin for palimpsests and anomalous pit craters on Ganymede and Callisto LPSC XIV. J Geophys Res Suppl 88:B71–B89CrossRefGoogle Scholar
  2. Moore JM, Malin MC (1988) Dome craters on Ganymede, Geophys. Res. Letters 15(3):225–228Google Scholar
  3. Passey QR, Shoemaker EM (1982) Craters and basins on Ganymede and Callisto – morphological indicators of crustal evolution, in: satellites of Jupiter. University of Arizona Press, TucsonGoogle Scholar
  4. Schenk PM (1996) Ganymede crater database. LPI. http://www.lpi.usra.edu/resources/gc/gchome.html
  5. Schenk PM, Chapman CR, Zahnle K, Moore JM (2004) Ages and interiors: the cratering record of the Galilean Satellites. In: Bagenal F, Dowling TE, McKinnon WB (eds) Jupiter: the planet, satellites and magnetosphere. Cambridge University Press, Cambridge, p 719Google Scholar

Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  1. 1.Planetary Science Research GroupEötvös Loránd University, Institute of Geography and Earth SciencesBudapestHungary