Major element ratios of Mercury's surface from MESSENGER

Major element ratios of Mercury's surface from MESSENGER
Major element ratios of Mercury's surface from MESSENGER Major-element composition of Mercury's surface materials, as measured by the MESSENGER XRS during the first Mercury year of the mission. Mercury has lower ratio of aluminum to silicon and a higher ratio of magnesium to silicon than typical lunar surface materials and terrestrial basalts, indicating a lower fraction of the common mineral plagioclase feldspar, and also indicating that Mercury has a distinct origin from the Moon and Earth. NASA / JHUAPL / CIW