Mercury's Surface: Preliminary Description and Interpretation from Mariner 10 Pictures

Science  12 Jul 1974:
Vol. 185, Issue 4146, pp. 169-179
DOI: 10.1126/science.185.4146.169


The surface morphology and optical properties of Mercury resemble those of the moon in remarkable detail and record a very similar sequence of events. Chemical and mineralogical similarity of the outer layers of Mercury and the moon is implied; Mercury is probably a differentiated planet with a large iron-rich core. Differentiation is inferred to have occurred very early. No evidence of atmospheric modification of landforms has been found. Large-scale scarps and ridges unlike lunar or martian features may reflect a unique period of planetary compression near the end of heavy bombardment by small planetesimals.