The Chemical Reactivity of the Martian Soil and Implications for Future Missions

Zent, A. P.; McKay, Christopher P.

doi:10.1006/icar.1994.1047

Cited by 209 publications

(125 citation statements)

References 0 publications

Supporting

Mentioning

123

Contrasting

Order By: Relevance

“…The oxidative reactivity of the Martian soil as measured by the Viking Biology Experiments (and exhibited on the organics of a certain nutrient by releasing O 2 and CO 2 (refs 65,66)), requires a mix of oxidants in the soil including oxidants capable of destroying organics 57,67 . À assay.…”

Section: Discussionmentioning

confidence: 99%

Evidence for photochemical production of reactive oxygen species in desert soils

et al. 2015

Self Cite

View full text Add to dashboard Cite

The combination of intense solar radiation and soil desiccation creates a short circuit in the biogeochemical carbon cycle, where soils release significant amounts of CO 2 and reactive nitrogen oxides by abiotic oxidation. Here we show that desert soils accumulate metal superoxides and peroxides at higher levels than non-desert soils. We also show the photogeneration of equimolar superoxide and hydroxyl radical in desiccated and aqueous soils, respectively, by a photo-induced electron transfer mechanism supported by their mineralogical composition. Reactivity of desert soils is further supported by the generation of hydroxyl radical via aqueous extracts in the dark. Our findings extend to desert soils the photogeneration of reactive oxygen species by certain mineral oxides and also explain previous studies on desert soil organic oxidant chemistry and microbiology. Similar processes driven by ultraviolet radiation may be operating in the surface soils on Mars.

show abstract

Section: Discussionmentioning

confidence: 99%

Evidence for photochemical production of reactive oxygen species in desert soils

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…Zent and McKay, 1994]. Numerous attempts have been made in the laboratory to simulate the reactions seen in the Viking biological experiments, but, while some have mimicked certain aspects of the data, none have been entirely satisfactory [Klein, 1979;Zent and McKay, 1994], and the basis for the results seen on Mars remains obscure. Additional experiments, conducted on the surface of Mars, will be necessary if we are to unravel the true nature of the reactive materials observed in the Viking experiments.…”

Section: Relevant Viking Findingsmentioning

confidence: 99%

The search for life on Mars: What we learned from Viking

Klein¹

1998

J. Geophys. Res.

View full text Add to dashboard Cite

“…We are currently investigating the correlation between the charge density of phyllosilicates and the extent of their possible protective role on the organic molecules, adsorbed on or embedded within them, against the degradation effects of gamma and UV radiation, directly or via the generation of secondary reactive species such as peroxides (Chun et al, 1978;Zent and McKay, 1994). We shall compare the results with possible protective role of other minerals identified on martian soil.…”

Section: Discussionmentioning

confidence: 99%

Correlation Between the Extent of Catalytic Activity and Charge Density of Montmorillonites

et al. 2010

View full text Add to dashboard Cite

The clay mineral montmorillonite is a member of the phyllosilicate group of minerals, which has been detected on martian soil. Montmorillonite catalyzes the condensation of activated monomers to form RNA-like oligomers. Extent of catalysis, that is, the yield of oligomers, and the length of the longest oligomer formed in these reactions widely varies with the source of montmorillonite (i.e., the locality where the mineral is mined). This study was undertaken to establish whether there exists a correlation between the extent of catalytic property and the charge density of montmorillonites. Charge density was determined by saturating the montmorillonites with alkyl ammonium cations that contained increasing lengths of alkyl chains, [CH 3 þ , where n ¼ 3-16 and 18, and then measuring d (001) , interlayer spacing of the resulting montmorillonite-alkyl ammoniummontmorillonite complex by X-ray diffractometry (XRD).Results demonstrate that catalytic activity of montmorillonites with lower charge density is superior to that of higher charge density montmorillonite. They produce longer oligomers that contain 9 to 10 monomer units, while montmorillonite with high charge density catalyzes the formation of oligomers that contain only 4 monomer units.The charge density of montmorillonites can also be calculated from the chemical composition if elemental analysis data of the pure mineral are available. In the next mission to Mars, CheMin (Chemistry and Mineralogy), a combined X-ray diffraction/X-ray fluorescence instrument, will provide information on the mineralogical and elemental analysis of the samples. Possible significance of these results for planning the future missions to Mars for the search of organic compounds and extinct or extant life is discussed.

show abstract

The Chemical Reactivity of the Martian Soil and Implications for Future Missions

Cited by 209 publications

References 0 publications

Evidence for photochemical production of reactive oxygen species in desert soils

Evidence for photochemical production of reactive oxygen species in desert soils

The search for life on Mars: What we learned from Viking

Correlation Between the Extent of Catalytic Activity and Charge Density of Montmorillonites

Contact Info

Product

Resources

About