关于这张图
This image captured by NASA 2001 Mars Odyssey spacecraft shows part of Hyperboreae Undae, a dune field located between the north polar cap and Escorial Crater. This image was taken during northern spring and the dunes still have significant surface frost. The dunes "darken" with time as the frost sublimates from solar heating and the dark sands are revealed. Orbit Number: 61858 Latitude: 77.8284 Longitude: 309.388 Instrument: VIS Captured: 2015-11-24 04:12 http://photojournal.jpl.nasa.gov/catalog/PIA20237
