Photos of rocks on Mars.
Grooves carved in this rock through erosion by airborne sand show a past predominant wind direction (yellow arrows) that is distinctly different from modern prevailing winds measured by the Mars 2020 Perseverance Rover. Credit: Herkenhoff et al. [2023], Figure 1
Editors’ Highlights are summaries of recent papers by AGU’s journal editors.
Source: JGR: Planets

Rocks abraded by wind-blown sand particles are known as ventifacts, and the Mars 2020 Perseverance Rover has found many such rocks in Jezero Crater. The abrasions on ventifacts form narrow grooves that are oriented with the prevailing wind direction, preserving the dominant wind direction on the face of the rocks themselves.

Herkenhoff et al. [2023] find that the wind directions preserved in Jezero Crater’s ventifacts are distinctly different than the predominant directions measured by Perseverance’s own weather sensors and the directions implied by other aeolian indicators, such as dune and ripple migration. The disparity between the ventifact directions and the modern wind directions indicate the ventifacts were likely formed under a different climate. Mars’ climate varies naturally, as Earth’s does, through changes in the planet’s axial tilt and orbit over thousands and millions of years, but Mars’ climate may vary in more extreme ways. These Jezero Crater rocks may thus show a record of past climates, providing important ground-truth to how Mars’ climate has changed over time.   

Herkenhoff, K. E., Sullivan, R. J., Newman, C. E., Paar, G., Baker, M., Viúdez-Moreiras, D., et al. (2023). Comparison of Ventifact Orientations and Recent Wind Direction Indicators on the Floor of Jezero Crater, Mars. Journal of Geophysical Research: Planets, 128, e2022JE007599.

—Scott Guzewich, Associate Editor, JGR: Planets

Text © 2023. The authors. CC BY-NC-ND 3.0
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