MESSENGER's Gamma-ray and Neutron Spectrometer (GRNS) [720p]

Schematic illustration of the operation of MESSENGER's Gamma-ray and Neutron Spectrometer (GRNS). Galactic cosmic rays interact with the surface of Mercury to a depth of tens of centimeters, producing high-energy ("fast") neutrons. These neutrons further interact with surface material, resulting in the emission of gamma-rays with energies characteristic of the emitting elements and low-energy ("slow") neutrons. Naturally occurring radioactive elements such as potassium (K), thorium (Th), and uranium (U) also emit gamma-rays. Detection of the gamma-rays and neutrons by GRNS allows determination of the chemical composition of the surface.

credit: NASA/The Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

source: http://messenger.jhuapl.edu/news_room/presscon_multi9.html

Category:

Science & Technology