Experimental and theoretical simulation of sublimating dusty water ice with implications for D/H ratios of water ice on Comets and Mars

Persistent Link:
http://hdl.handle.net/10150/610231
Title:
Experimental and theoretical simulation of sublimating dusty water ice with implications for D/H ratios of water ice on Comets and Mars
Author:
Moores, John; Brown, Robert; Lauretta, Dante; Smith, Peter
Affiliation:
Lunar and Planetary Laboratory, Department of Planetary Sciences, University of Arizona, 1629 E University Blvd, Tucson, AZ 85721-0092, USA; Now at: Centre for Planetary Science and Exploration, Department of Physics and Astronomy, University of Western Ontario, 1151 Richmond Street, London, ON N6A 3 K7, Canada
Issue Date:
2012
Publisher:
BioMed Central
Citation:
Moores et al. Planetary Science 2012, 1:2 http://www.planetary-science.com/content/1/1/2
Journal:
Planetary Science
Rights:
© 2012 Moores et al; licensee Springer. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0)
Collection Information:
This item is part of the UA Faculty Publications collection. For more information this item or other items in the UA Campus Repository, contact the University of Arizona Libraries at repository@u.library.arizona.edu.
Abstract:
Sublimation experiments have been carried out to determine the effect of the mineral dust content of porous ices on the isotopic composition of the sublimate gas over medium (days to weeks) timescales. Whenever mineral dust of any kind was present, the D/H ratio of the sublimated gas was seen to decrease with time from the bulk ratio. Fractionations of up to 2.5 were observed for dust mixing ratios of 9 wt% and higher of JSC MARS-1 regolith simulant 1-10 mum crushed and sieved fraction. These favored the presence of the light isotope, H2O, in the gas phase. The more dust was added to the mixture, the more pronounced was this effect. Theoretical modeling of gas migration within the porous samples and adsorption on the excavated dust grains was undertaken to explain the results. Adsorption onto the dust grains is able to explain the low D/H ratios in the sublimate gas if adsorption favors retention of HDO over H2O. This leads to significant isotopic enrichment of HDO on the dust over time and depletion in the amount of HDO escaping the system as sublimate gas. This effect is significant for planetary bodies on which water moves mainly through the gas phase and a significant surface reservoir of dust may be found, such as on Comets and Mars. For each of these, inferences about the bulk water D/H ratio as inferred from gas phase measurements needs to be reassessed in light of the volatile cycling history of each body.PACS CODES:98.80.Ft Isotopes, abundances and evolution (astronomy)], 64.70.Hz Sublimation], 68.43.-h Adsorption at solid surfaces]
EISSN:
2191-2521
DOI:
10.1186/2191-2521-1-2
Keywords:
Stable Isotope Geochemistry; Sublimation; Icy Bodies; Adsorption of Water; Comets; Mars
Version:
Final published version
Additional Links:
http://www.planetary-science.com/content/1/1/2

Full metadata record

DC FieldValue Language
dc.contributor.authorMoores, Johnen
dc.contributor.authorBrown, Roberten
dc.contributor.authorLauretta, Danteen
dc.contributor.authorSmith, Peteren
dc.date.accessioned2016-05-20T09:01:41Z-
dc.date.available2016-05-20T09:01:41Z-
dc.date.issued2012en
dc.identifier.citationMoores et al. Planetary Science 2012, 1:2 http://www.planetary-science.com/content/1/1/2en
dc.identifier.doi10.1186/2191-2521-1-2en
dc.identifier.urihttp://hdl.handle.net/10150/610231-
dc.description.abstractSublimation experiments have been carried out to determine the effect of the mineral dust content of porous ices on the isotopic composition of the sublimate gas over medium (days to weeks) timescales. Whenever mineral dust of any kind was present, the D/H ratio of the sublimated gas was seen to decrease with time from the bulk ratio. Fractionations of up to 2.5 were observed for dust mixing ratios of 9 wt% and higher of JSC MARS-1 regolith simulant 1-10 mum crushed and sieved fraction. These favored the presence of the light isotope, H2O, in the gas phase. The more dust was added to the mixture, the more pronounced was this effect. Theoretical modeling of gas migration within the porous samples and adsorption on the excavated dust grains was undertaken to explain the results. Adsorption onto the dust grains is able to explain the low D/H ratios in the sublimate gas if adsorption favors retention of HDO over H2O. This leads to significant isotopic enrichment of HDO on the dust over time and depletion in the amount of HDO escaping the system as sublimate gas. This effect is significant for planetary bodies on which water moves mainly through the gas phase and a significant surface reservoir of dust may be found, such as on Comets and Mars. For each of these, inferences about the bulk water D/H ratio as inferred from gas phase measurements needs to be reassessed in light of the volatile cycling history of each body.PACS CODES:98.80.Ft Isotopes, abundances and evolution (astronomy)], 64.70.Hz Sublimation], 68.43.-h Adsorption at solid surfaces]en
dc.language.isoenen
dc.publisherBioMed Centralen
dc.relation.urlhttp://www.planetary-science.com/content/1/1/2en
dc.rights© 2012 Moores et al; licensee Springer. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0)en
dc.subjectStable Isotope Geochemistryen
dc.subjectSublimationen
dc.subjectIcy Bodiesen
dc.subjectAdsorption of Wateren
dc.subjectCometsen
dc.subjectMarsen
dc.titleExperimental and theoretical simulation of sublimating dusty water ice with implications for D/H ratios of water ice on Comets and Marsen
dc.typeArticleen
dc.identifier.eissn2191-2521en
dc.contributor.departmentLunar and Planetary Laboratory, Department of Planetary Sciences, University of Arizona, 1629 E University Blvd, Tucson, AZ 85721-0092, USAen
dc.contributor.departmentNow at: Centre for Planetary Science and Exploration, Department of Physics and Astronomy, University of Western Ontario, 1151 Richmond Street, London, ON N6A 3 K7, Canadaen
dc.identifier.journalPlanetary Scienceen
dc.description.collectioninformationThis item is part of the UA Faculty Publications collection. For more information this item or other items in the UA Campus Repository, contact the University of Arizona Libraries at repository@u.library.arizona.edu.en
dc.eprint.versionFinal published versionen
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