Keywords: mars nasa mro jpl landscape science space geology blackandwhite monochrome texture abstract black and white Spiders on Mounds: This landform is uniquely Martian, formed in the spring as seasonal dry ice turns directly into gas. NASA/JPL/University of Arizona (5 km across; www.uahirise.org/ESP_046562_1005) Spiders on Mounds: This landform is uniquely Martian, formed in the spring as seasonal dry ice turns directly into gas. NASA/JPL/University of Arizona (5 km across; www.uahirise.org/ESP_046562_1005) |