Gale Crater Methane SGM2010 Dust Frozen CO2 Oceanus Borealis Environment3. The Martian Rocks Bassanite (or gypsum)
Mars Society Switzerland
Signs of Hydrated Calcium Sulfates in Martian Rocks This graphic from NASA's Curiosity mission shows an analysis of the composition of two rocks called "Crest" and "Rapitan" in the "Yellowknife Bay" area of Mars. Curiosity's "Chemistry and Camera" ("ChemCam") instrument zapped light-colored veins in these rocks with its laser and found that they contain sulfur and hydrogen. Scientists interpret these results to mean Crest and Rapitan's light-colored veins contain hydrated calcium sulfates. These minerals could be gypsum or bassanite. On Earth, calcium sulfates like gypsum form frequently in veins when relatively dilute fluid circulates at low to moderate temperatures. The ChemCam analysis helped Curiosity mission managers decide where to use the rover's drill for the first time. The ChemCam instrument analysed Crest on Dec. 13, 2012 and Rapitan on Dec. 23, 2012. Image Credit: NASA/JPL-Caltech/LANL/CNES/IRAP/LPGNantes/CNRS
Rapitan Crest
Smectite Clay
Coronation's Chemicals This is the first laser spectrum from the ChemCam instrument on NASA's Curiosity rover, sent back from Mars on August 19, 2012. The plot shows emission lines from different elements present in the target, a rock near the rover's landing site dubbed "Coronation" (see inset). ChemCam's detectors observe light in the ultraviolet (UV), violet, visible and near-infrared ranges using three spectrometers, covering wavelengths from 240 to 850 nanometers. The light is produced when ChemCam's laser pulse strikes a target, generating ionized gases in the form of plasma, which is then analyzed by the spectrometers and their detectors for the presence of specific elements. The detectors can collect up to 16,000 counts produced by the light in any of its 6,144 channels for each laser shot. The plot is a composite of spectra taken over 30 laser shots at a single 0.4-millimeter diameter spot on the target. An inset on the left shows detail for the minor elements titanium and manganese in the 398-to-404-nanometer range. An inset at the right shows the hydrogen and carbon peaks. The carbon peak was from the carbon dioxide in Mars' air. The hydrogen peak was only present on the first laser shot, indicating that the element was only on the very surface of the rock. Magnesium was also slightly enriched on the surface. The heights of the peaks do not directly indicate the relative abundances of the elements in the rock, as some emission lines are more easily excited than others. A preliminarily analysis indicates the spectrum is consistent with basalt , a type of volcanic rock, which is known from previous missions to be abundant on Mars. Coronation is about 7.6 centimeters across, and located about 1.5 meters from the rover and about 2.7 meters from ChemCam on the mast. Image Credit: NASA/JPL-Caltech/LANL/CNES/IRAP
Page 1 Page 2Six month after the landing of Curiosity, what did we learn? (Page 3)
Geology & Atmosphere
Major Gases Released from Drilled Samples of the "John Klein" Rock An analysis of a drilled rock sample from NASA's Curiosity rover shows the presence of water, carbon dioxide, oxygen, sulfur dioxide, and hydrogen sulfide released on heating. The results analyzing the high temperature water release are consistent with smectite clay minerals. Curiosity's Sample Analysis at Mars (SAM) instrument suite conducted the analysis. The first step in the analysis of a portion of this drilled sample was to heat the sample in a quartz oven to 835 degrees Celsius and analyze the gases as they were released using SAM's quadrupole mass spectrometer (QMS). The signatures of more than five hundred mass values were sampled during the heating of this drilled sample and analyzed by the QMS. Five are shown in the graph. These traces are diagnostic of water, carbon dioxide, oxygen, and two forms of sulfur (sulfur dioxide, the oxidized form, and hydrogen sulfide, the reduced form) measured by the QMS. The second step in the analysis was to send a portion of the gas released from the sample to the tunable laser spectrometer (TLS) to measure isotopes of carbon, oxygen and hydrogen, in both water and carbon dioxide. The ratio of deuterium (a heavy form of hydrogen) to the lighter, more abundant form of hydrogen was lower than the deuterium-to-hydrogen ratio measured by SAM in more loosely bound water in the sample from the "Rocknest" drift . The high deuterium-to-hydrogen ratio in water in the Mars atmosphere is a signature of the lighter hydrogen more rapidly escaping to space over geological time. The third step in the analysis was to inject gas trapped during the heating process into SAM's third instrument, the gas chromatograph. Individual compounds separate out in time in a long capillary column in this instrument and are then introduced into the QMS. The gas chromatograph mass spectrometer is a prime tool in the SAM search for organic compounds.The ratio of reduced species to oxidized species released by the SAM ovens is significantly higher in this drilled bedrock than in the previously scooped dust samples. These results indicate a significant amount of available chemical energy because oxidized and less oxidized versions of molecules are present. This result, combined with suitable aqueous conditions at this site in the distant past, made this a potentially habitable environment . The SAM analysis was conducted on Sol 200 (the 200th Martian day of Curosity's operations, which was Feb. 27, 2013, on Earth). Image Credit: NASA/JPL-Caltech/GSFC
Pressures Changes