Data from the Observatoire pour la Mineralogie, l'Eau, les Glaces et l'Activité (OMEGA) instrument on the European Space Agency's Mars Express spacecraft superimposed on a Mars Orbiter Laser Altimeter map (lower image) carried on Mars Global Surveyor. (reference)

color key:

hemetite map

This map was originally published as Jean-Pierre Bibring et al. "Global Mineralogical and Aqueous Mars History Derived from OMEGA/Mars Express Data", Science 21 April 2006: Vol. 312. no. 5772, pp. 400 - 404 and can be accessed online at http://www.sciencemag.org/cgi/content/full/312/5772/400