Search for life on Mars in surface samples: Lessons from the 1999 Marsokhod rover field experiment

Journal of Geophysical Research E: Planets
By: , and 

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Abstract

The Marsokhod 1999 field experiment in the Mojave Desert included a simulation of a rover-based sample selection mission. As part of this mission, a test was made of strategies and analytical techniques for identifying past or present life in environments expected to be present on Mars. A combination of visual clues from high-resolution images and the detection of an important biomolecule (chlorophyll) with visible/near-infrared (NIR) spectroscopy led to the successful identification of a rock with evidence of cryptoendolithic organisms. The sample was identified in high-resolution images (3 times the resolution of the Imager for Mars Pathfinder camera) on the basis of a green tinge and textural information suggesting the presence of a thin, partially missing exfoliating layer revealing the organisms. The presence of chlorophyll bands in similar samples was observed in visible/NIR spectra of samples in the field and later confirmed in the laboratory using the same spectrometer. Raman spectroscopy in the laboratory, simulating a remote measurement technique, also detected evidence of carotenoids in samples from the same area. Laboratory analysis confirmed that the subsurface layer of the rock is inhabited by a community of coccoid Chroococcidioposis cyanobacteria. The identification of minerals in the field, including carbonates and serpentine, that are associated with aqueous processes was also demonstrated using the visible/NIR spectrometer. Other lessons learned that are applicable to future rover missions include the benefits of web-based programs for target selection and for daily mission planning and the need for involvement of the science team in optimizing image compression schemes based on the retention of visual signature characteristics.

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Publication type Article
Publication Subtype Journal Article
Title Search for life on Mars in surface samples: Lessons from the 1999 Marsokhod rover field experiment
Series title Journal of Geophysical Research E: Planets
DOI 10.1029/1999JE001159
Volume 106
Issue E4
Year Published 2001
Language English
Publisher American Geophysical Union
Description 8 p.
First page 7713
Last page 7720
Country United States
State California
Other Geospatial Mojave Desert
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