First topographic map of Mercury

The first global topographic map of the planet Mercury was published on 6 May 2016 by NASA's Planetary Data System. The 3D map was created using more than 100,000 images taken between 2011 and 2015 by NASA's MESSENGER orbiter.

There were some partial topographical maps generated earlier, but these relied on data from the Mercury Laser Altimeter, which only operated while the spacecraft was over the planet's northern hemisphere. (MESSENGER's eliptical orbit meant that it was too far from the planet for the MLA to work when it was over the southern hemisphere.)

This new map was generated using computer analysis of the shadows and other distortions in MESSENGER orbital photography. The entire surface of the planet was imaged several times over, allowing the researchers to compare images taken under different lighting conditions and extrapolate the terrain from the shadows and other distortions.