Figure 11-28: R I V U X G
Seasons on the Martian Surface (a) This springtime view from Viking Lander 1 shows rocks that resemble volcanic rocks on Earth (see Figure 9-19a). They are thought to be part of an ancient lava flow that was broken apart by crater-forming asteroid impacts. Fine-grained debris has formed sand dunes. (b) This picture was taken during midwinter at the Viking Lander 2 site. Freezing carbon dioxide condenses onto water-ice crystals or dust grains in the atmosphere, causing them to fall to the ground and coat the surface with frost. This frost lasted for about a hundred days.
Seasons on the Martian Surface (a) This springtime view from Viking Lander 1 shows rocks that resemble volcanic rocks on Earth (see Figure 9-19a). They are thought to be part of an ancient lava flow that was broken apart by crater-forming asteroid impacts. Fine-grained debris has formed sand dunes. (b) This picture was taken during midwinter at the Viking Lander 2 site. Freezing carbon dioxide condenses onto water-ice crystals or dust grains in the atmosphere, causing them to fall to the ground and coat the surface with frost. This frost lasted for about a hundred days.
(a: Dr. Edwin Bell II/NSSDC/GSFC/NASA; b: NASA)