Neutron Mars . ... Credit Copyright: Mars Odyssey , GRS Team , LANL , NASA Explanation: Looking for water on Mars, researchers using detectors on board the orbiting Mars Odyssey spacecraft have created this false-color global map of energetic neutrons from the otherwise Red Planet . ... But if the martian soil contains hydrogen, it seriously absorbs energetic scattered neutrons. ... Thus, bluer shades in the above map correspond to larger presumed concentrations of near-surface water ice. ...