A and B: white liquid flowing over Mars rock; C to D: 40 cm (width of rover’s wheel). The above image has been enlarged 300% and cropped from mars.nasa.gov/msl/multimedia/raw/?rawid=1183ML00536700305…
Original caption: “This image was taken by Mastcam: Left (MAST_LEFT) onboard NASA’s Mars rover Curiosity on Sol 1183 (2015-12-04 15:54:57 UTC). Image Credit: NASA/JPL-Caltech/MSSS”