关于这张图
Siton Undae is a large dune field located in the northern plains near Escorial Crater. Siton Undae is west of the crater and is one of three dune fields near the crater. The nearby north polar cap is dissected by Chasma Boreale, which exposes an ice free surface. This image was collected during early spring in the northern hemisphere. The bright appearance of the dunes is due to frost cover. As the season progresses the dunes become darker as the frost disappears. The Odyssey spacecraft has spent over 15 years in orbit around Mars, circling the planet more than 69000 times. It holds the rec…
