1fa1dd55__Ion_Propulsion___Dawn_Mission__Grades_9_12
[Dawn Instrumentation Module] Cosmic rays interact with surface soil constituents, causing them to emit gamma rays of specific energies. Gamma Ray spectroscopes detect these characteristic emissions to identify the presence of elements, water and ice on surface of Vesta and Ceres [Grades 9-12] 
Nuclear reactions convert a fraction of the mass of interacting particles into energy.
Education > Structure and Properties of Matter: Ion Propulsion | Dawn Mission
Grades 9-12