Wavy alien dune fields stretch across Mars | Space photo of the day for Sept. 11, 2026

A dune field on Mars, as seen by the Mars Reconnaissance Orbiter.(Image credit: NASA/JPL-Caltech/University of Arizona)Are those purple, wavy, alien thumbprints? Or perhaps an otherworldly ocean? Nope! It's actually a dune field on Mars, colored purple.What is it?Across the Martian surface are all sorts of unique features in the rocky, dusty surface material. In this false-color image, snapped by the HiRISE (High Resolution Imaging Science Experiment) camera on NASA's Mars Reconnaissance Orbiter