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Wind interaction with falling ejecta: Origin of the parabolic features on Venus
Author(s) -
Vervack Ronald J.,
Melosh H. Jay
Publication year - 1992
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/91gl02812
Subject(s) - ejecta , impact crater , venus , atmosphere (unit) , atmospheric sciences , atmosphere of venus , projectile , prevailing winds , geology , physics , astrobiology , meteorology , astrophysics , quantum mechanics , supernova
Unusual parabolic features associated with impact craters have been observed by Magellan on Venus. A strong correlation exists between the orientation of the features and the zonal winds on Venus. We propose a quantitative model in which the parabolic features are produced by the interaction of the zonal winds with material ejected ballistically from the impact crater. As the ejecta particles fall through the atmosphere, the winds transport them downwind from their entry point, smaller particles being transported a greater distance. Since the ejecta distribution is initially axially symmetric and smaller particles are thrown farther from the crater, the winds blow the particles on the upwind side back upon one another, leading to a pile‐up of material. On the downwind side, the winds disperse the ejecta particles and no pile‐up occurs. The resulting thickness distribution on the Venusian surface matches the observed parabolic features closely. The dual parabolic feature associated with the crater Carson is also explained by this model.