NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Dunes and Microdunes on Venus: Why Were So Few Found in the Magellan Data?A search through cycle 1, 2, and 3 Magellan radar data covering 98% of the surface of Venus revealed very few dunes. Only two possible dune fields and several areas that may contain microdunes smaller than the resolution of the images (75 m) were identified. The Aglaonice dune field was identified in the cycle I images by the specular returns characteristic of dune faces oriented perpendicular to the radar illumination. Cycle 1 and 2 data of the Fortuna-Meshkenet dune field indicate that there has been no noticeable movement of the dunes over an 8-month period. The dunes, which are oriented both parallel and perpendicular to the radar illumination, appear to be dark features on a brighter substrate. Bright and dark patches that were visible in either cycle 1 or 2 data, but not both, allowed identification of several regions in the southern part of Venus that may contain microdunes. The microdunes are associated with several parabolic crater deposits in the region and are probably similar to those formed in wind tunnel experiments under Venus-like conditions. Bragg scattering and/or subpixel reflections from the near-normal face on asymmetric microdunes may account for these bright and dark patches. Look-angle effects and the lack of sufficient sand-size particles seem to be the most likely reasons so few dunes were identified in Magellan data. Insufficient wind speeds, thinness of sand cover, and difficulty in identifying isolated dunes may also be contributors to the scarcity of dunes.
Document ID
19990116099
Acquisition Source
Jet Propulsion Laboratory
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Weitz, Catherine M.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
Plaut, Jeffrey J.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
Greeley, Ronald
(Arizona State Univ. Tempe, AZ United States)
Saunders, R. Steven
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
Date Acquired
August 19, 2013
Publication Date
January 1, 1994
Publication Information
Publication: ICARUS
Publisher: Academic Press, Inc.
Volume: 112
ISSN: 0019-1035
Subject Category
Lunar And Planetary Exploration
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available