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Water content of the Martian soil: Laboratory simulations of reflectance spectra

Yen, Albert S. and Murray, Bruce C. and Rossman, George R. (1998) Water content of the Martian soil: Laboratory simulations of reflectance spectra. Journal of Geophysical Research E, 103 (E5). pp. 11125-11133. ISSN 0148-0227. doi:10.1029/98JE00739.

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Reflectance spectra from the surface of Mars collected by instruments such as the imaging spectrometer (ISM) onboard the 1988 Soviet Phobos 2 spacecraft exhibit strong 3 μm absorption features that have long been attributed to hydrated materials on the Martian surface. This interpretation is consistent with a series of chemical weathering models suggesting an abundance of palagonites, clays, and other hydrated mineral phases in the Martian fines. Little work, however, has been done to constrain the actual water content of the Martian surface materials. New laboratory data presented here show that the ISM spectra are consistent with up to 4% water by weight and that the deep hydration features observed in the spacecraft data could be due to less than 0.5% water if the hydrated phases are present in the form of grain coatings. These results are consistent with the somewhat uncertain in situ measurements obtained by the Viking landers which yielded approximately 2 wt % water from samples heated to 500°C. On the basis of this work, we expect the TEGA instrument on the Mars '98 lander to find less than 4% adsorbed or bound water in the upper few centimeters of the Martian soil.

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Rossman, George R.0000-0002-4571-6884
Additional Information:© 1998 by the American Geophysical Union. Received June 13, 1997; revised February 27, 1998; accepted March 5, 1998. We thank Wendy Calvin and Scott Murchie for thorough reviews and helpful discussions which have greatly improved this manuscript. Stephane Erard provided us with digital versions of ISM spectra for comparison with our laboratory data. Aaron Zent provided the Pahala Ash, and Lazlo Keszthelyi collected the basalt samples for our experiments. Albert Yen acknowledges the support of the NASA Graduate Student Researchers Program. George Rossman acknowledges the support of NSF EAR 9218980.
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NASA Graduate Student Researchers ProgramUNSPECIFIED
Issue or Number:E5
Record Number:CaltechAUTHORS:20130416-131617343
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Official Citation:Yen, A. S., B. C. Murray, and G. R. Rossman (1998), Water content of the Martian soil: Laboratory simulations of reflectance spectra, J. Geophys. Res., 103(E5), 11125–11133, doi:10.1029/98JE00739
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:37972
Deposited By: Tony Diaz
Deposited On:16 Apr 2013 23:55
Last Modified:09 Nov 2021 23:32

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