Titre du document

Lunar cratering and erosion from Orbiter 5 photographs

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Nom du Corpus

AstroConcepts

Auteur(s)
  • Clark R. Chapman
  • Joel A. Mosher
  • Gene Simmons
Résumé

Incremental diameter?frequency relations for twelve lunar regions are presented for four classes of craters (sharp to soft), 0.02 to 2 km diameter. Sharp craters have similar frequencies on all regions. Soft?crater densities vary by factors up to 100, not only between highlands and maria, but between maria regions. Highlands lack the large excesses on the maria of soft craters; these excesses cluster about 0.8 km near Hyginus and at Ranger 8 and 9 impact sites, but about 0.2 km on Mare Imbrium, and at both or intermediate sizes for Bonpland and Sinus Medii. No simple large?scale erosive process on impact craters yields such excesses or the observed regional variations in crater density and percentage mix of sharp to soft craters. Crater populations for individual areas also seem inconsistent with saturation impact gardening: observable craters are not geometrically saturated, and frequency relations are not strictly parallel with slopes of ?3. Uniform or episodic erosive or covering processes also generally fail to produce the observed excesses of soft craters, and a covering episode should produce a bump in the frequency of sharp craters that is not observed. These conclusions hold independently of any regional or vertical variations in structure that might affect energy?size scaling. Layering inferred from other studies apparently was not produced by impact gardening; the depth of the gardened layer (or effective depth of accretion or depletion) is probably less than 1 meter. Our data are consistent with this plausible (but not unique) interpretation: (1) Subsequent to extensive early blanketing, impact cratering has occurred on highlands and old crater walls, with a probable admixture of endogenic and secondary cratering; (2) The maria underwent similar processes, but have many additional endogenic craters, probably collapse features formed in lava flows. Our counts of craters by class should also be useful for refining alternative models for cratering and erosion.

Langue(s) du document
Anglais
Année de publication
1970
Revue

Journal of Geophysical Research

Éditeur
Wiley
Type de publication
journal
Type de document
article
Présence de XML structuré
Non
Version de PDF
1.3
Score de qualité du texte
10
Nom du concept
  • Space debris
Mots-clés d’auteur
  • Extraterrestrial Geology: Moon
  • Moon: Surface Features
  • Planetology: Moon
Catégories Science-Metrix
  • 1 - natural sciences ; 2 - earth & environmental sciences ; 3 - meteorology & atmospheric sciences
Catégories Scopus
  • 1 - Physical Sciences ; 2 - Earth and Planetary Sciences ; 3 - Palaeontology
  • 1 - Physical Sciences ; 2 - Earth and Planetary Sciences ; 3 - Space and Planetary Science
  • 1 - Physical Sciences ; 2 - Earth and Planetary Sciences ; 3 - Earth and Planetary Sciences (miscellaneous)
  • 1 - Physical Sciences ; 2 - Earth and Planetary Sciences ; 3 - Atmospheric Science
  • 1 - Physical Sciences ; 2 - Earth and Planetary Sciences ; 3 - Earth-Surface Processes
  • 1 - Physical Sciences ; 2 - Earth and Planetary Sciences ; 3 - Geochemistry and Petrology
  • 1 - Life Sciences ; 2 - Agricultural and Biological Sciences ; 3 - Soil Science
  • 1 - Physical Sciences ; 2 - Environmental Science ; 3 - Water Science and Technology
  • 1 - Physical Sciences ; 2 - Environmental Science ; 3 - Ecology
  • 1 - Life Sciences ; 2 - Agricultural and Biological Sciences ; 3 - Aquatic Science
  • 1 - Life Sciences ; 2 - Agricultural and Biological Sciences ; 3 - Forestry
  • 1 - Physical Sciences ; 2 - Earth and Planetary Sciences ; 3 - Oceanography
  • 1 - Physical Sciences ; 2 - Earth and Planetary Sciences ; 3 - Geophysics
Catégories WoS
  • 1 - science ; 2 - geosciences, multidisciplinary
Identifiant ISTEX
DE5F494DB92DA24FBEE1CA56BF55C626E98DE9E1
ark:/67375/WNG-CXCT7MB8-C
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