Divining Rod Designed for Mars

Detecting water underground does not require a magical stick. Neutrons reflecting out of the soil can indicate the presence of water or ice. A novel instrument that can detect those neutrons is planned for NASA’s next rover mission to Mars.
Because neutrons penetrate most materials, neutron beams and detectors are often used to study crystal structure, as well as explore oil and mineral reserves underground. The same physics motivates the Dynamic Albedo of Neutrons (DAN) instrument, a contribution from the Federal Space Agency of Russia to the Mars Science Laboratory (MSL) that is scheduled to launch next year. The goal of the DAN instrument is to use neutrons to detect water that might be lurking underneath the rover as it moves along the martian surface.