Aaron P. Zent

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The transection and superposition relationships among channels, chaos, surface materials units, and other features in the circum-Chryse region of Mars were used to evaluate relative age relationships and evolution of flood events. Channels and chaos in contact (with one another) were treated as single discrete flood-carved systems. Some outflow channel(More)
In the past few years, it has become increasingly apparent that perchlorate (ClO(4)(-)) is present on all continents, except the polar regions where it had not yet been assessed, and that it may have a significant natural source. Here, we report on the discovery of perchlorate in soil and ice from several Antarctic Dry Valleys (ADVs) where concentrations(More)
The Phoenix mission investigated patterned ground and weather in the northern arctic region of Mars for 5 months starting 25 May 2008 (solar longitude between 76.5 degrees and 148 degrees ). A shallow ice table was uncovered by the robotic arm in the center and edge of a nearby polygon at depths of 5 to 18 centimeters. In late summer, snowfall and frost(More)
P. H. Smith, L. Tamppari, R. E. Arvidson, D. Bass, D. Blaney, W. Boynton, A. Carswell, D. Catling, B. Clark, T. Duck, E. DeJong, D. Fisher, W. Goetz, P. Gunnlaugsson, M. Hecht, V. Hipkin, J. Hoffman, S. Hviid, H. Keller, S. Kounaves, C. F. Lange, M. Lemmon, M. Madsen, M. Malin, W. Markiewicz, J. Marshall, C. McKay, M. Mellon, D. Michelangeli, D. Ming, R.(More)
The Urey organic and oxidant detector consists of a suite of instruments designed to search for several classes of organic molecules in the martian regolith and ascertain whether these compounds were produced by biotic or abiotic processes using chirality measurements. These experiments will also determine the chemical stability of organic molecules within(More)
Hydrogen peroxide chemisorbed on titanium dioxide (peroxide-modified titanium dioxide) is investigated as a chemical analog to the putative soil oxidants responsible for the chemical reactivity seen in the Viking biology experiments. When peroxide-modified titanium dioxide (anatase) was exposed to a solution similar to the Viking labeled release (LR)(More)
[1] A model is presented here to explain the generation of surface material on Mars using chemical, magnetic, and spectroscopic data from Mars and geologic analogs from terrestrial sites. One basic premise is that the dust/soil units are not derived exclusively from local rocks, but are rather a product of global, and possibly remote, weathering processes.(More)
  • A P Zent
  • Journal of geophysical research
  • 1998
A revised model of the diffusion of H2O2 through the Martian regolith is presented, which argues that oxidant diffusion may be more efficient than previously thought. Recent models of the adsorption of H2O at Mars-like conditions indicate that it adsorbs more poorly than previously believed. H2O adsorption is a necessary proxy for peroxide adsorption; hence(More)