<< We think Mars had a thicker atmosphere in the past that might have formed smaller wind-drag ripples or even have prevented their formation altogether. Thus, the size of preserved wind-drag ripples, where found in Martian sandstones, may have recorded the thinning of the atmosphere >>
Guy Webster, Robert Perkins. NASA Rover's Sand-Dune Studies Yield Surprise. June 30, 2016.
M. G. A. Lapotre, R. C. Ewing, et al. Large wind ripples on Mars: A record of atmospheric evolution. Science. 01 Jul 2016:Vol. 353, Issue 6294, pp. 55-58DOI: 10.1126/science.aaf3206