Small dune or sand ripple, seen by Navcam and Hazcam.
NASA description (top): This image was taken by Navcam: Left B (NAV_LEFT_B) onboard NASA’s Mars rover Curiosity on Sol 668 (2014-06-23 12:28:36 UTC).
NASA description: (bottom): This image was taken by Front Hazcam: Left B (FHAZ_LEFT_B) onboard NASA’s Mars rover Curiosity on Sol 668 (2014-06-23 12:54:25 UTC).
Sol 668 raw images (from all cameras), and Curiosity’s latest location map.