Curiosity update: Well I’ll be DANed!

Sol 2148, August 22, 2018, update by MSL scientist Melissa Rice: Curiosity is probing the subsurface today with its Dynamic Albedo of Neutrons (DAN) instrument. At three different times, Curiosity will use DAN in its “active” mode for 20 minutes, sending pulses of neutrons into the ground beneath the rover, and then listening for the neutrons that are scattered back to the instrument. Hydrogen atoms in water will reduce the energy of the neutrons, so the scattered signal that DAN receives will tell us about how much water might be present in the form of hydrated minerals and amorphous phases, to a depth of 1 m beneath the surface. Curiosity is using DAN multiple times today because the neutron output from the DAN Pulsing Neutron Generator (PNG) has decreased over time (though it is well beyond its expected life), and we hope… [More at link]