2010 Annual Science Report
University of Wisconsin Reporting | SEP 2009 – AUG 2010
Project 5A: Astrobiology Studies at the Utah Mars Desert Research Station in Support of Current and Future Mars Missions
Pascale Ehrenfreund participated to Crew #77 at the Mars Desert Research Station (MDRS) in Utah in February 2009. The MDRS project was initiated by the Mars Society in 2000 and consists of a habitat complex optimized for a 6-person crew and includes a greenhouse and astronomical observatory. The goal of this field campaign sponsored by ESA, NASA and the international lunar exploration working group (ILEWG) was to demonstrate instrument capabilities in support of current and future planetary missions, to validate a procedure for Martian surface in-situ and return science, and to study human performance aspects. Special emphasis was given to sample collection in the geologically rich vicinity of MDRS and subsequent analysis of organic molecules and microorganisms in the soil to simulate the search for life with field instrumentation.
Crew 77 at MDRS has collected soil samples from different locations and depths and investigated those soils in the MDRS laboratory with Terra XRD/XRF (X-ray diffraction/X-ray fluorescence) from InXitu Inc. and a Raman InPhotonics (LAS-750-300 Class 3b embedded Diode Laser, 785 nm wavelength, 300 mW max continuous wave energy) instrument. Furthermore we measured some soil properties including pH value and elemental composition of Ca, K, P, Mg, and nitrate. Salt concentrations were also estimated by obtaining soil conductivity data. Polymerase chain reaction (PCR) was successfully used for the in-situ analysis of microbial communities. Post-analysis included the investigation of microbial diversity and the analysis of the mineral matrix of planetary soil analogs from the Utah desert. Culture-independent molecular analyses directed at ribosomal RNA genes revealed the presence of all three domains of life (Archaea, Bacteria and Eukarya).
Post-analysis of sterile collected selected samples from 10 different location at the vicinity of MDRS have been performed using Solid Phase Microextraction (SPME) and Gas Chromatography/ Mass Spectrometry (GC/MS) to extract and measure polycyclic aromatic hydrocarbons, X-ray diffraction and infrared spectroscopy to determine the mineral content, laser desorption mass spectrometry to understand the high molecular carbon fraction and investigation about the relative contributions of different phyla groups to microbial communities. Table 1 shows the variety in mineralogy as analyzed by X-ray diffraction.
Table 1: X-ray diffraction data of Utah soil samples (relative abundance in %) (Martins et al. 2010).
A main goal for this field research program is to understand the relation of mineral matrix, organic fraction and biota in the soil.
The main scientific finding include
- low abundances of polycyclic aromatic hydrocarbons
- presence of macromolecular matter (kerogen)
- strong diversity of mineralogy (clay, quartz and gypsum)
- presence of biota of all three domains with significant heterogeneity
- extraordinary wide variety of extremophiles, mainly from the domain Bacteria but also Archaea
The data will be compiled in a special issue of the International Journal of Astrobiology.