Scientists at the U.S. Geological Survey (USGS) have released a new global geologic map of Mars, which records the distribution of geologic units and landforms on the planet’s surface through time. It is based on the unprecedented variety, quality, and quantity of remotely sensed data acquired since the Viking Orbiters. These data have provided morphologic, topographic, spectral, thermophysical, radar sounding, and other observations for integration, analysis, and interpretation in support of geologic mapping. In particular, the precise topographic mapping now available through laser altimetry has enabled a consistent portrayal of the surface for global mapping. Also, they use thermal infrared image bases, which tend to be less affected by atmospheric haze and are reliable for analysis of surface morphology and texture at even higher resolutions.
Links: USGS Map 3292 hompeage with further resources, PDF with detailed key (file is 35 MB), external link to movie of rotating geologic surface of Mars (Credit: Jennifer LaVista/USGS), NY Times article describing the new map, Eos article by Ken Tanaka (link to PDF).