The High Resolution Imaging Science Experiment, or HiRISE, instrument aboard the Mars Reconnaissance Orbiter sends back a steady stream of spectacular images revealing subtle and not-so-subtle surface features on the red planet. In this view, late winter sunlight, striking the martian surface at a very low angle, contributed to an intriguing HiRISE image of sand dunes dusted with carbon dioxide frost and dust. Dark spots could be areas where underlying sand is exposed thanks to earlier defrosting activity. In a tweet about the photo, the HiRISE team wrote “It was hard not to title this ‘The Duck of Mars.'” The image is the first in a new series of observations designed to track seasonal processes. The complete photo strip is available here. Can you spot the duck?