Chemical interpretation of Viking Lander 1 life detection experiment

Ballou, E. V.; Wood, Peter C.; Wydeven, T.; Lehwalt, M. E.; Mack, R.

doi:10.1038/271644a0

Cited by 93 publications

(51 citation statements)

References 6 publications

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“…7) (34), which does not contradict the only SSA estimate available to date of 17 m 2 g −1 derived by the Viking Gas Exchange Experiment (72). The relatively low SSA suspected for the The ratio between the mean night and day S/B is 1.003, indicating no sign of water enrichment at night.…”

Section: Hydration Of the Amorphous Phase And Specific Surface Area Omentioning

confidence: 66%

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

Meslin

Gasnault

Forni

et al. 2013

Science

225

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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Section: Hydration Of the Amorphous Phase And Specific Surface Area Omentioning

confidence: 66%

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

Meslin

Gasnault

Forni

et al. 2013

Science

225

200

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“…about the Martian weather. Although both landers were equipped with instruments for the detection of microbial life in the Martian soil, no evidence for present or past life was found (Ballou et al 1978). However, the interesting places on Mars where microbial life forms could exist have not been explored until today.…”

Section: Mars Polar Capsmentioning

confidence: 99%

Access to glacial and subglacial environments in the Solar System by melting probe technology

Ulamec

Biele

Funke

et al. 2006

Rev Environ Sci Biotechnol

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A key aspect for understanding the biological and biochemical environment of subglacial waters, on Earth or other planets and moons in the Solar system, is the analysis of material embedded in or underneath icy layers on the surface. In particular the Antarctic lakes (most prominently Lake Vostok) but also the icy crust of Jupiter's moon Europa or the polar caps of Mars require such investigation. One possible technique to penetrate thick ice layers with small and reliable probes is by melting, which does not require the heavy, complex and expensive equipment of a drilling rig. While melting probes have successfully been used for terrestrial applications e.g. in Antarctic ice, their performance in vacuum is different and theory needs confirmation by tests. Thus, a vacuum chamber has been used to perform a series of melting tests in cold (liquid nitrogen cooled) water ice samples. The feasibility of the method was demonstrated and the energy demand for a space mission could be estimated. Due to the high energy demand in case of extraterrestrial application (e.g. Europa or polar caps of Mars), only heating with radioactive isotopes seems feasible for reaching greater depths. The necessary power is driven by the desired penetration velocity (approximately linearly) and the dimensions of the probe (proportional to the cross section). In comparison to traditional drilling techniques the application of a melting probe for exploration of Antarctic lakes offers the advantage that biological contamination is minimized, since the Probe can be sterilized and the melting channel freezes immediately after the probe's passage, inhibiting exchange with the surface layers and the atmosphere. In order to understand the physical and chemical nature of the ice layers, as well as for analysing the underlying water body, a melting probe needs to be equipped with a suite of scientific instruments that are capable of e.g. determining the chemical and isotopic composition of the embedded or dissolved materials.

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“…These were parts per billion for organics with three or more carbons, and parts per million for organic molecules with et al, 1994]. The existence of alkali and alkaline earth superoxides [Oyama et al, 1976;Oyama and Berdhal, 1977;Ballou et al, 1978] have been proposed to explain the evolution of 0 2 in the GEX, as well as to provide a destruction mechanism for organic compounds. Photochemical processes have also been used to suggest an explanation for the creation of oxides in the Martian soil [Hunten, 1979[Hunten, , 1987.…”

Section: Introductionmentioning

confidence: 99%

Organic degradation under simulated Martian conditions

1997

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Abstract. We report on laboratory experiments which simulate the breakdown of organic compounds under Martian surface conditions. Chambers containing Mars-analog soil mixed with the amino acid glycine were evacuated and filled to 100 mbar pressure with a Martian atmosphere gas mixture and then irradiated with a broad spectrum Xe lamp. Headspace gases were periodically withdrawn and analyzed via gas chromatography for the presence of organic gases expected to be decomposition products of the glycine. The quantum efficiency for the decomposition of glycine by light at wavelengths from 2000 to 2400 A was measured to be 1.46 + 1.0 x 10 -6 molecules/photon. Scaled to Mars, this represents an organic destruction rate of 2.24 _+ 1.2 x 10 -4 g of C m -2 yr-1. We compare this degradation rate with the rate that organic compounds are brought to Mars as a result of meteoritic infall to show that organic compounds are destroyed on Mars at rates far exceeding the rate that they are deposited by meteorites. Thus the fact that no organic compounds were found on Mars by the Viking Lander Gas Chromatograph Mass Spectrometer experiment can be explained without invoking the presence of strong oxidants in the surface soils. The organic destruction rate may be considered as an upper bound for the globally averaged biomass production rate of extant organisms at the surface of Mars. This upper bound is comparable to the slow growing cryptoendolithic microbial communities found in dry Antarctica deserts. Finally, comparing these organic destruction rates to recently reported experiments on the stability of carbonate on the surface of Mars, we t'ind that organic compounds may currently be more stable than calcite.

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Chemical interpretation of Viking Lander 1 life detection experiment

Cited by 93 publications

References 6 publications

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

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

Access to glacial and subglacial environments in the Solar System by melting probe technology

Organic degradation under simulated Martian conditions

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