The Viking X Ray Fluorescence Experiment: Analytical methods and early results

Clark, B. C.; Baird, A. K.; Rose, Harry J.; Toulmin, Priestley; Christian, R. P.; Kelliher, Warren C.; Castro, A. J.; Rowe, Catherine D.; Keil, K.; Huss, G. R.

doi:10.1029/js082i028p04577

Cited by 140 publications

(51 citation statements)

References 15 publications

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“…The APXS on Sojourner rover of Mars Pathfinder mission measured the elemental composition of rocks and soils, to find a rock called "Barnacle Bill" and "Yogi" with silicic or andesitic composition, while "Scooby Doo" and the background soils are basaltic (Rieder et al, 1997), which is consistent with the Viking XRF results (Clark et al, 1977). This suggests the evidence that the terrestrial-like igneous processes occurred to compose diversity of composition sufficient to produce andesitic rocks, and that at least some local geologic areas consist non-basaltic composition.…”

Section: Introductionsupporting

confidence: 72%

Application of altimeter experiments of Planet-B orbiter to the exploration of Martian surface and subsurface layers

Okada

Ono

2014

Earth Planet Sp

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Application of altimeter experiment of Planet-B orbiter to the exploration of Martian surface and subsurface layers is planned by using the ALT mode data from the "PWS (Plasma Waves and Sounder)" instrument. The topographic profile along-the-track from the orbiter to the nadir point of Martian surface can be obtained in detail owing to the high accuracy of the PWS altimetry of about 20 m. The characteristics of altimeter echo intensities are also applicable to obtain the electromagnetic properties which were functions of bulk density, humidity, and abundance of ferromagnetic minerals of the uppermost layer of Martian surfaces. The surface macroscopic roughness was also studied since the rise time was slower for the echo from the rougher surface. Another possibility of the application of the altimeter experiment can be given by identifying the subsurface echoes and it is used as a probe for sensing physical properties from tens to hundreds meters below the surface, including possible exploration of liquid water.

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Section: Introductionsupporting

confidence: 72%

Application of altimeter experiments of Planet-B orbiter to the exploration of Martian surface and subsurface layers

Okada

Ono

2014

Earth Planet Sp

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“…Before the Mars Science Laboratory mission, the bulk chemical composition of the soil was characterized in situ at five different locations on Mars by Viking 1 and 2 (16,17), Mars Pathfinder (18), and the Mars Exploration Rovers (MERs) both at Meridiani Planum (19) and in Gusev Crater (20). Both bright dust and dark soil deposits on opposite sides of the planet were found to be very similar (21).…”

Section: Soil Diversity and Hydration As Observed By Chemcam At Gale mentioning

confidence: 99%

Soil Diversity and Hydration as Observed by ChemCam at Gale Crater, Mars

Meslin

Gasnault

Forni

et al. 2013

Science

229

200

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International audienceThe ChemCam instrument, which provides insight into martian soil chemistry at the submillimeter scale, identified two principal soil types along the Curiosity rover traverse: a fine-grained mafic type and a locally derived, coarse-grained felsic type. The mafic soil component is representative of widespread martian soils and is similar in composition to the martian dust. It possesses a ubiquitous hydrogen signature in ChemCam spectra, corresponding to the hydration of the amorphous phases found in the soil by the CheMin instrument. This hydration likely accounts for an important fraction of the global hydration of the surface seen by previous orbital measurements. ChemCam analyses did not reveal any significant exchange of water vapor between the regolith and the atmosphere. These observations provide constraints on the nature of the amorphous phases and their hydration

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“…The ideal gas constant for Earth's atmosphere (RE) is 287 J/(kg K), and Martian atmosphere Ra4 is 192 J/(kg K). Gas density was made to be the same in the wind tunnel as Based upon chemical properties measured by spacecraft and remote sensing, iron-rich montmorillonite clay mixtures and some palagonites serve as acceptable analog Martian dust materials [Clark et al, 1977]. However, these materials are not readily available for use in the wind tunnel.…”

Section: Experimental Facility and Measuring Systemsmentioning

confidence: 99%

Aeolian behavior of dust in a simulated Martian environment

White¹,

Lacchia²,

Greeley³

et al. 1997

J. Geophys. Res.

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Abstract. The behavior of aeolian dust, particles 1-2 microns (/•m) in diameter, was analyzed in a simulated Martian environment. Three main areas have been investigated: (1) characterizing spectral and aeolian properties of Martian particles and natural windblown terrestrial dust in order to identify a suitable surrogate Martian dust, (2) emplacement of the material in the simulated Martian environment, and (3) experimental procedures and testing in the Martian Surface Wind Tunnel (MARSWIT). The first phase of the study involved choosing a terrestrial dust that closely resembled Martian dust. Data accumulated from various sources suggest that Martian dust is derived from the weathering of basaltic parent material, nontronite clay being a good candidate composition. A commercial clay, Carbondale Red Clay (CRC), was determined to be an appropriate surrogate Martian dust. Using a compressed air-dust ejection system, an airentrained dust cloud was generated which settled to cover the test section in the MARSWIT. This method best replicated the natural aerodynamic settling process presumed to exist on Mars. Low-pressure experiments were performed in the MARSWIT facility located at the NASA Ames Research Center, Moffett Field, California. Two separate wind tunnel floors were used for these experiments; one provided an aerodynamically smooth-surface flow, and the other was an aerodynamically rough-surface flow. Initial and momentary particle movement was recorded at friction velocities as low as 2 m/s. However, the "dust" never reached fluid saltation threshold because individual particles less than 10/•m typically do not saltate, but pass into suspension. An estimated 7 2 dust flux of 3.7 x 10-g/cm s was determined for a friction velocity of 2 m/s. This flux could suspend about i0,000 metric tons of dust per second over the surface of Mars. The dust behavior on the smooth surface was markedly different than on the rough surface under Martian conditions. Application of the processes described above to the Martian environment suggests that on rocky surfaces dust suspension would first occur, whereas smooth plains would require higher wind speeds for dust entrainment. 1.' IntroductionMartian dust storms have been known to last a period of 9 months and can grow to envelop the planet. As on Earth, dust particles are distributed in the Martian atmosphere by size. As dust storms subside, heavier and larger particles, present at lower altitudes, settle to the surface first, followed by gradual deposition of lighter and smaller particles suspended higher above the surface.The term "dust" generally refers to particles less than 62.5 microns (/•m) in diameter and is divided into two groups: silt, consisting of particles between 62.5 and 5/•m in diameter, and clay, consisting of particles less than 5 /•m in diameter [Pye, 1987]. For this study, only particles less than 10/•m in diameter were analyzed. Therefore the term "dust" refers to material less than 10 /•m in particle diameter. This particle size is representative of Marti...

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The Viking X Ray Fluorescence Experiment: Analytical methods and early results

Cited by 140 publications

References 15 publications

Application of altimeter experiments of Planet-B orbiter to the exploration of Martian surface and subsurface layers

Application of altimeter experiments of Planet-B orbiter to the exploration of Martian surface and subsurface layers

Soil Diversity and Hydration as Observed by ChemCam at Gale Crater, Mars

Aeolian behavior of dust in a simulated Martian environment

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