The first global topographic map of Mercury has been released by the USGS Astrogeology Science Center, in collaboration with Arizona State University, Johns Hopkins University Applied Physics Laboratory, Carnegie Institute of Washington, and NASA. This map provides the first comprehensive view of Mercury’s entire surface illustrating the geologic and tectonic characteristics of the planet closest to the sun.
More than 100,000 images acquired from the Mercury Dual Imaging System (MDIS) camera on board the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft were used to derive the digital elevation model (DEM) at 665 m/pixel. The highly elliptical orbit of MESSENGER and the close proximity to the sun resulted in a dataset of images with a large variety of disparate geometric and illumination characteristics. This challenging dataset led the USGS to implement new and robust techniques to detect features in images and to match corresponding features between overlapping images. This feature-based approach is the first step in the process of refining image position and orientation parameters, which are critical for the accurate determination of elevation data.
The global map reveals 10 km of vertical relief of Mercury’s surface with lows of –5,380 m and highs of 4,481 m at its extremes. The DEM provided the basis for image orthorectification of global monochrome and color mosaics released by the MESSENGER team.
Color-coded shaded relief derived from the global DEM in a Robinson projection. Elevations are in meters relative to the reference radius 2,349.4 km. One degree of longitude at the equator is 42.6 km.