Message #9134

[rockessence]

http://astrogeology.usgs.gov/Gallery/MoviesAndAnimations/media/mars_tes_summercap.gif

Mars Summer Polar Cap

Type: Animated GIF

The animation is composed of two composite albedo images of the martian north polar cap from the martian mid-summer in 1999 (May 9-21) and 2001 (March 27 - April 7). The color scheme represents albedo (surface brightness) where red is the brightest and purple is the darkest. Regions with albedo less than .23 are soil (purple-blue). Regions brighter than 0.23 are covered with water ice. The brightest regions (red) are covered with frost from condensing water in the atmosphere. The animation shows interannual variations in the cap brightness, suggesting a variation in frost formation from year to year. A greater understanding of the processes that cause summer frost formation on the northern cap will help NASA and the scientific community discover how water on Mars is transported.