New insights concerning the early bombardment history on Mercury
The surface of Mercury is rather different from those of well-known rocky bodies like the Moon and Mars. Early images from the Mariner 10 spacecraft unveiled a planet covered by smooth plains and cratered plains of unclear origin. A team led by Dr. Simone Marchi, collaborating with the MESSENGER team, including Dr. Clark Chapman of the SwRI Planetary Science Directorate, studied the surface to better understand if the plains were formed by volcanic flows or composed of material ejected from the planet’s giant impact basins.
Recent images from NASA’s MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) spacecraft provided new insights showing that at least the younger plains resulted from vigorous volcanic activity. Yet scientists were unable to establish limits on how far into the past this volcanic activity may have occurred, or how much of the planet’s surface may have been resurfaced by very old volcanic plains.