Martian soil with volatile halogens
Examples of different soil types used to reveal the potential of (a) trench at Gusev ~20 cm wide and 11 cm deep. (b) Disturbed soil at Gusev with 5 cm diameter Mossabauer nose print. (c) Meridiani soil sample brushed with the RAT, 3x3 cm. (d) Meridiani undisturbed soil 3x3 cm, colorized with Pancam.
These white deposits are the remnants of an ancient hydrothermal system in the Nili Patera Caldera of the Syrtis Major volcanic complex.