User:SpaceCat13/Chemistry and Camera complex

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Instrumentation[edit]

LIBS[edit]

Five frame ChemCam RMI mosaic (right) of the rock "Chantrey," colorized using the right MastCam (M-100) image (left). Image Credit: NASA / JPL / LANL / MSSS / Justin Cowart

ChemCam marks the first use of Laser Induced Breakdown Spectroscopy (LIBS) as part of a planetary science mission[1][2]. The laser is positioned on the mast of the Curiosity rover and focused by the telescope that also resides on the mast, while the spectrometer is housed in the rover's body. Typically, the laser fires 30 shots at a single point, gathering spectroscopic readings from the vaporized rock for each laser shot, and samples multiple points on a chosen target. For bedrock observations, the first 5 shots of a point are discarded as they are considered to be contaminated by Martian dust[3]. The remaining shots of one point are averaged together for chemical composition calculations[1][2][4]. It is common for there to be 9 or 10 points of analysis on any given target, but this is not always the case. Some targets have as few as 4 points while some targets have 20 points.

Remote Micro-Imager[edit]

The Remote Micro-Imager is primarily used to capture high-resolution, black and white images of ChemCam targets for context and documentation[4]. Usually, an image of the target of interest is captured before and after the laser is fired. Often, the laser makes "LIBS pits" that can be visible in the RMI to show where the laser sampled specifically on a particular target. The resolution of the RMI is higher than the black and white navigational camera (navcam) and the color mast cameras (mastcam).

Long Distance Imaging[edit]

The remote micro-imager (RMI) is primarily used to obtain close-up images of targets sampled by ChemCam, but it can also be used to gather high-resolution images of distant outcrops and landscapes[5]. The RMI has a higher spatial resolution than the mastcam M100 camera, which is a color camera also capable of imaging nearby objects or distant geologic features[5]. The RMI has been used by the mission for reconnaissance of up-coming terrain as well as imaging distant features such as the rim of Gale Crater.

Scientific Contributions[edit]

ChemCam has been used, in conjunction with other instruments of the Curiosity rover, to make advancements in understanding the chemical composition of rocks and soils on Mars. LIBS makes it possible to detect and quantify the major oxides: SiO2, Al2O3, FeOT, MgO, TiO2, CaO, Na2O, and K2O of bedrock targets[1][2][4]. There are distinguishable geologic units determined from orbital analyses that have been confirmed by averaged bedrock compositions determined from ChemCam and other instruments aboard Curiosity[6]. ChemCam has also quantified soil chemistry. ChemCam has seen two distinct soil types at Gale crater: a fine-grained mafic material that is more representative of global Martian soils or dust and a coarse-grained felsic material that originates from local Gale crater bedrock.[3] ChemCam has the capability to measure minor or trace elements such as lithium, manganese, strontium, and rubidium[7][8]. ChemCam has measured MnO up to 25 wt% in fracture fills that suggests Mars was once a more oxygenating environment[7].

References[edit]

  1. ^ a b c "Pre-flight calibration and initial data processing for the ChemCam laser-induced breakdown spectroscopy instrument on the Mars Science Laboratory rover". Spectrochimica Acta Part B: Atomic Spectroscopy. 82: 1–27. 2013-04-01. doi:10.1016/j.sab.2013.02.003. ISSN 0584-8547.
  2. ^ a b c Maurice, S.; Clegg, S. M.; Wiens, R. C.; Gasnault, O.; Rapin, W.; Forni, O.; Cousin, A.; Sautter, V.; Mangold, N.; Deit, L. Le; Nachon, M. (2016-03-30). "ChemCam activities and discoveries during the nominal mission of the Mars Science Laboratory in Gale crater, Mars". Journal of Analytical Atomic Spectrometry. 31 (4): 863–889. doi:10.1039/C5JA00417A. ISSN 1364-5544.
  3. ^ a b Meslin, P.- Y.; Gasnault, O.; Forni, O.; Schroder, S.; Cousin, A.; Berger, G.; Clegg, S. M.; Lasue, J.; Maurice, S.; Sautter, V.; Le Mouelic, S. (2013-09-27). "Soil Diversity and Hydration as Observed by ChemCam at Gale Crater, Mars". Science. 341 (6153): 1238670–1238670. doi:10.1126/science.1238670. ISSN 0036-8075.
  4. ^ a b c Maurice, S.; Wiens, R. C.; Saccoccio, M.; Barraclough, B.; Gasnault, O.; Forni, O.; Mangold, N.; Baratoux, D.; Bender, S.; Berger, G.; Bernardin, J. (2012). "The ChemCam Instrument Suite on the Mars Science Laboratory (MSL) Rover: Science Objectives and Mast Unit Description". Space Science Reviews. 170 (1–4): 95–166. doi:10.1007/s11214-012-9912-2. ISSN 0038-6308.
  5. ^ a b Le Mouélic, S.; Gasnault, O.; Herkenhoff, K. E.; Bridges, N. T.; Langevin, Y.; Mangold, N.; Maurice, S.; Wiens, R. C.; Pinet, P.; Newsom, H. E.; Deen, R. G. (2015-03-15). "The ChemCam Remote Micro-Imager at Gale crater: Review of the first year of operations on Mars". Icarus. Special Issue: First Year of MSL. 249: 93–107. doi:10.1016/j.icarus.2014.05.030. ISSN 0019-1035.
  6. ^ Frydenvang, J.; Mangold, N.; Wiens, R. C.; Fraeman, A. A.; Edgar, L. A.; Fedo, C. M.; L'Haridon, J.; Bedford, C. C.; Gupta, S.; Grotzinger, J. P.; Bridges, J. C. (2020). "The Chemostratigraphy of the Murray Formation and Role of Diagenesis at Vera Rubin Ridge in Gale Crater, Mars, as Observed by the ChemCam Instrument". Journal of Geophysical Research: Planets. 125 (9): e2019JE006320. doi:10.1029/2019JE006320. ISSN 2169-9100.
  7. ^ a b Lanza, Nina L.; Wiens, Roger C.; Arvidson, Raymond E.; Clark, Benton C.; Fischer, Woodward W.; Gellert, Ralf; Grotzinger, John P.; Hurowitz, Joel A.; McLennan, Scott M.; Morris, Richard V.; Rice, Melissa S. (2016). "Oxidation of manganese in an ancient aquifer, Kimberley formation, Gale crater, Mars". Geophysical Research Letters. 43 (14): 7398–7407. doi:10.1002/2016GL069109. ISSN 1944-8007.
  8. ^ Payré, V.; Fabre, C.; Cousin, A.; Sautter, V.; Wiens, R. C.; Forni, O.; Gasnault, O.; Mangold, N.; Meslin, P.-Y.; Lasue, J.; Ollila, A. (2017). "Alkali trace elements in Gale crater, Mars, with ChemCam: Calibration update and geological implications". Journal of Geophysical Research: Planets. 122 (3): 650–679. doi:10.1002/2016JE005201. ISSN 2169-9100.
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