Gentle Perseverance Lifts the Veil on Martian Dust

Abstract

Observations with sensitive photodiode detectors on the Perseverance rover (Hueso et al., 2023, https://doi.org/10.1029/2022JE007516; Vicente‐Retortillo et al., 2023, https://doi.org/10.1029/2022je007672) to detect dust devils and track formation, and movies of the Ingenuity helicopter's downwash impingement on the Martian surface (Lemmon et al., 2022a, https://doi.org/10.1029/2022je007605; Lemmon et al., 2022b, https://doi.org/10.1029/2022gl100126), together with in‐situ meteorological data, give new insights into the important problem of dust‐lifting on Mars, a phenomenon which influenced the lifetime of recent rovers and landers. These results, together with new low‐gravity wind tunnel experiments on parabolic flights and interpretation of the large blast pattern from lander retrorockets, indicate that particle motion and visible darkening on Mars can result from aerodynamic pressures of only 1–5 Pa, considerably less than previously thought.

Dry Downhill Particle Motion on Mars

“…Much of the surface of Mars is covered by dust and sand, and ways to mobilize these grains are important for many studies. The scientific problems range from the entrainment of dust into the atmosphere by wind and saltation, dust devils, or electrostatics (Greeley et al 1980;Cantor et al 1999;Montabone et al 2005;Kok & Renno 2008;Kok et al 2012;Reiss & Lorenz 2016;Becker et al 2022;Lorenz 2023;Toledo et al 2023) to the formation of geomorphologic features like dunes (Chojnacki et al 2011;Bridges et al 2012aBridges et al , 2012bKok et al 2012). Quite generally, mobilization is important for all kinds of slopes on Mars because their angle is set by downhill motion.…”