Mapping Ions around Mercury: Nasa Messenger Mission Date presented 29 Sept 2011

Date Presented: September 29, 2011, at a NASA Press Briefing Instrument: The Fast Imaging Plasma Spectrometer (FIPS) Of Interest: This image is an artistic rendering of the global distribution of ionized sodium (Na) and helium (He) near the planet Mercury. Sodium exhibits distinct maxima near the magnetic cusps, where neutral atoms are likely liberated from the surface by solar wind ion bombardment. Helium is much more uniformly distributed, such as would be expected if the dominant source process were evaporation from a helium-saturated surface.

Credit: University of Michigan (inset courtesy AAAS/Science)