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 crosses the center of the dune field and was collected in early spring. The Odyssey spacecraft has spent over 15 years in orbit around Mars, circling the planet more than 69000 times. It holds the record for longest working spacecraft at Mars. THEMIS, the IR/VIS camera system, has collected data for the entire mission and …