SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS

A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 44, ISSUE 5 - March 10, 2006

91 LUNAR AND PLANETARY SCIENCE AND EXPLORATION
Includes planetology; selenology; meteorites; comets; and manned and unmanned planetary and lunar flights.

For spacecraft design or space stations see 18 Spacecraft Design, Testing and Performance.

20060006983

Adsorption Water-related Potential Chemical and Biological Processes in the Upper Martian Surface

Mohlmann, D.; Astrobiology; Dec 2005; ISSN 1531-1074; Volume 5, 6, pp. 770-7; In English; Copyright; ONLINE:http://dx.doi.org/10.1089/ast.2005.5.770; Avail.: Other Sources

Mars Odyssey has given strong evidence for the existence of water in the upper martian surface at equatorial latitudes.The water content, which corresponds to the hydrogen in the soil, can regionally reach values up to about 15%. This wateris mainly in the form of structurally and partially irreversibly bound ‘crystal’ water, and of reversibly bound and partiallyunfrozen adsorption water. This adsorption water, which has ‘liquid-like’ properties as a two dimensional fluid or film, cantrigger-in the presence of ultraviolet light and in concentrations similar to what has been measured on Mars-photocatalyticprocesses that are important for martian surface chemistry. The consequences of the diurnally variable presence of adsorptionwater on the chemistry and hypothetical biological processes at and in the upper martian surface at equatorial and mid-latitudesare discussed in terms of water-related environmental aspects for chemical and hypothetical life processes on Mars. NLM

Activity (Biology); Adsorption; Chemical Reactions; Mars (Planet); Mars Surface; Surface Properties; Water

20060006984

A Search for Chiral Signatures on Mars

Sparks, William B.; Hough, James H.; Bergeron, Louis E.; Astrobiology; Dec 2005; ISSN 1531-1074; Volume 5, 6, pp. 737-48; In English; Copyright; ONLINE: http://dx.doi.org/10.1089/ast.2005.5.737; Avail.: Other Sources

It is thought that the chiral molecules of living material can induce circular polarization in light at levels much higher than expected from abiotic processes.We therefore obtained high quality imaging circular polarimetry of the martian surface during the favorable opposition of 2003 to seek evidence of anomalous optical activity. We used two narrow-band filters covering 43% of the martian surface, 15% of it in-depth. With polarization noise levels \h0.1% (4.3 upper limits 0.2-0.3%) and spatial resolution 210 km, we did not find any regions of circular polarization. When data were averaged over the observed face of the planet, we did see a small non-zero circular polarization 0.02%, which may be due to effects associated with the opposition configuration though it is at the limit of the instrumental capability. Our observations covered only a small fraction of parameter space, so although we obtained a null result, we cannot exclude the presence of optical activity at other wavelengths, in other locations, or at higher spatial resolution. NLM

Chirality; Isomers; Mars (Planet); Signatures

20060007010

Soil Moisture Retrieval from Optical and Thermal Spaceborne Remote Sensing

Verstraeten, W. W.; Veroustraete, F.; Feyen, J.; Communications in agricultural and applied biological sciences; 2005; ISSN 1379-1176; Volume 70, 2, pp. 27-30; In English; Copyright; Avail.: Other Sources

No abstract available.

Remote Sensing; Soil Moisture; Soils; Water

Source: NASA