Crater formation and modification on the icy satellites of Uranus and Saturn: Depth/diameter and central peak occurrence

Journal Article · Mon Apr 10 00:00:00 EDT 1989 · Journal of Geophysical Research; (USA)

DOI:https://doi.org/10.1029/JB094iB04p03813· OSTI ID:5833767

Schenk, P M ^[1]

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1. California Institute of Technology, Pasadena (USA)

Depth/diameters (d/D) for fresh craters on the intermediate-sized icy satellites of Uranus and Saturn have been determined using photoclinometry and shadow lengths, and are compared with similar measurements on the terrestrial planets. Simple bowl-shaped craters on icy satellites, including those on Miranda for which the highest resolution data are available, are systematically 20-40% shallower than on the terrestrial planets. This pronounced difference between crater depths on icy and rocky surfaces indicates that differences in impact velocity or surface gravity are not as important as the differences in mechanical properties between ice and rock in controlling simple crater morphology. Experimental impact studies indicate that differences in material properties such as angle of internal friction can control crater depth. Complex craters on the icy satellites become significantly deeper with increasing crater diameters, unlike complex craters on terrestrial planets, which are nearly constant in depth. Central peaks, and hence floor rebound, are also volumetrically and morphologically more prominent than wall slumping (rim collapse) on the icy satellites. The transition diameter from simple to complex morphology is inversely correlated with gravity, as it is on the terrestrial planets, but at significantly smaller diameters than would be expected from a simple extrapolation of the terrestrial trend. The distinct, systematic differences between crater morphology on icy and rocky worlds indicate that gross material property differences between rock and ices play a key role in crater formation and modification, but gravity is still the primary driving force.

• OSTI ID: 5833767
• Journal Information: Journal of Geophysical Research; (USA), Vol. 94:B4; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
SATELLITES
CRATERS
SATURN PLANET
URANUS PLANET
COMPARATIVE EVALUATIONS
DEPTH
GRAVITATION
ICE
IMPACT SHOCK
INTERNAL FRICTION
MECHANICAL PROPERTIES
MODIFICATIONS
MORPHOLOGY
ROCKS
CAVITIES
DIMENSIONS
FRICTION
PLANETS
640107* - Astrophysics & Cosmology- Planetary Phenomena