Research Objectives:
Project researchers have developed the SPISE3 instrument package, a portable, non-destructive suite of spectroscopic life detection instruments designed to detect subtle chemical biosignatures associated with the activities of life. Without touching the rocks, the instruments can detect some of the biosignatures of endolithic microbial communities. The project's goal is to develop the tools and strategies for life detection in preparation for in situ life detection missions to Mars and other planets, where the evidence for life may be very subtle.
The instrument suite consists of a spectroradiometer, portable gas chromatograph, and UV-VIS fluorescence spectrometer/Raman band detector. Investigators will also use a Raman spectrometer for providing mineralogical identification and context. After gathering data from cryptoendolithic communities in the Mojave Desert, and in the arctic (Svalbard), this austral summer project team members will non-destructively measure the signatures of the organisms in rocks in the Dry Valley environment of Antarctica. SPISE3 may become an important tool for rapidly assessing the potential of a rock (or even an outcrop) as a habitat for endolithic life.
The hypotheses to be tested are:
1. That one can reliably and reproducibly detect chemical biosignatures, which are differentiable from geochemical signatures.
2. That biosignatures are observable over various spatial scales which, in part, define how far away one can be from a sample or how much sample is needed for chemical biosignatures to be observable.
3. That time-resolved studies of chemical fluctuations can distinguish fluxes associated with metabolism from those associated with abiological, geochemical activities.
4.That microbial endolithic communities living in cold deserts will exhibit different chemical signatures than those adapted to life in hot deserts, and these differences will be observable in terms of spatial and temporal scales and chemical concentrations.
5.The chemistry of the sandstone hosting endolithic communities in the Antarctic Dry Valleys is relatively simple, mostly Silicon and Oxygen from the almost pure quartz mineral content. There are a variety of endolithic communities in the Mojave desert that inhabit more mineralogically and chemically complex rocks and sediment, e.g., mixed carbonates, silicates and evaporite rocks. What does the addition of more complex chemistry do to the instruments' ability to differentiate between geological and biological contributions to the chemical environment, both in terms of chemical and spatial separation?
