Dr. David Blake of the Exobiology Branch will be presenting an invited paper entitled “First results from the CheMin, DAN and SAM instruments on Mars Science Laboratory” at the American Geophysical Meeting in San Francisco on Monday, December 3, 2012.
Dr. Blake will present the first quantitative mineralogical results from the CheMin instrument, collected at a location called “Rocknest” in Gale Crater. CheMin analyzed portions of three scoops of material collected and sieved by Curiosity’s sample processing system. Portions of the third scoop were delivered to both the CheMin and SAM instruments, so that both mineralogical and volatile-organic analyses could be conducted on the same material. Figure 1 below shows a 2-dimensional image of the diffraction pattern from the third scoop of material. Figure 2 (side photo) shows the 1-dimensional diffractogram resulting from the data shown in Figure 1, together with the quantitative mineralogical results. This is the first quantitative analysis of Mars soil ever performed, and it corroborates what scientists have thought about Mars soil from less definitive measurements obtained from the MER rovers. In addition to what minerals are present, CheMin can place limits on the concentrations of minerals that are not seen. For example, carbonates and perchlorates, if present, must be below the detection limit of ~0.5 wt%. There is also about 50 wt% X-ray amorphous material (non-crystalline or nanophase materials) present in the pattern, and the CheMin team is at work to determine its quantitative amount and composition.