K. E. Herkenhoff1, R. J. Sullivan2,
C. E. Newman3, G. Paar4, M.
Baker5, D. Viúdez-Moreiras6, J. W.
Ashley7, A. Bechtold8, J. I.
Nuñez9
1U.S. Geological Survey Astrogeology Science Center,
Flagstaff, AZ 86001
2Cornell University, Ithaca, NY 14853
3Aeolis Research, Chandler, AZ 85224
4Joanneum Research, 8010 Graz, Austria
5Smithsonian National Air and Space Museum,
Washington, DC 20560
6Centro de Astrobiologia, Madrid, Spain
7NASA Jet Propulsion Laboratory, California Institute
of Technology, Pasadena, CA 91101
8University of Vienna, Austria
9Applied Physics Laboratory, Johns Hopkins University,
Laurel, MD 20723
Corresponding author: Ken Herkenhoff
(kherkenhoff@usgs.gov)
Key Points:
- The orientations of linear wind abrasion features on ventifacts record
the direction of ancient winds that formed them.
- Measurements of current and recent wind directions in Jezero crater
differ significantly from the inferred direction of ancient winds.
- As observed at other locations on Mars, these differences suggest a
change in the climate regime at these locations.
Abstract
Wind-abraded rocks and aeolian bedforms have been observed at the Mars
2020 Perseverance landing site, providing evidence for recent and
older wind directions. This study reports orientations of aeolian
features measured in Perseverance images to infer formative wind
directions. It compares these measurements with orbital observations,
climate model predictions, and wind data acquired by the Mars
Environmental Dynamics Analyzer. Three-dimensional orientations of flute
textures on rocks, regolith wind tails extending from behind obstacles,
and other aeolian features were measured using Digital Terrain Models
(DTMs) derived from Mastcam-Z and navigation camera (Navcam) stereo
images. Orientations of rock flutes measured in images acquired through
Sol (martian day) 400 yielded a mean azimuth of 94° ± 7° (wind from the
west). However, similar measurements of regolith wind tails indicate
that recent sand-driving winds have been blowing from the
east-southeast, nearly the opposite direction (mean azimuth = 285° ±
15°). Atmospheric modeling generally predicts net annual sand transport
from the east-southeast at present, consistent with Perseveranceregolith wind tail and orbital observations. The orientation of
ventifact flutes thus suggests that they were formed under a different
climate regime. Differences in orientations of recent and paleo-wind
indicators have been noted at other Mars landing sites and may result
from major orbital/axial changes that can cause significant changes in
atmospheric circulation. Orientation differences between modern and
older wind direction indicators at Jezero are useful clues to the
climate history of the region.