HR: 08:45h
AN: P41D-04    [Abstracts]
TI: Investigation of Life in the Atacama Desert by Astrobiology Rover
AU: * Wettergreen, D
EM: dsw@ri.cmu.edu
AF: Robotics Institute, Carnegie Mellon University 5000 Forbes Avenue, Pittsburgh, PA 15213 United States
AU: Cabrol, N
EM: nathalie.cabrol@mail.arc.nasa.gov
AF: NASA Ames/SETI Institute, Space Science Division MS 245-3, Moffett Field, CA 95035-1000 United States
AB: The Atacama Desert is the most arid region on Earth and in several ways analogous to Mars. It has been suggested that the interior of the desert is the most lifeless place on Earth, yet it is known that microorganisms exist on rocks and in soils where the desert meets the coastal range. The Life in the Atacama (LITA) project is investigating the distribution and diversity of life and habitats in the desert using an rover guided by a remote science team. The Atacama Desert presents an excellent analogue to Mars because it is extremely dry, but also, like Mars it experiences high levels of ultraviolet radiation due to its altitude and atmospheric transparency. The soils in the Atacama have been found to be particularly high in oxidants, which lead to the rapid breakdown of organic material. The result is that in some regions of desert almost no biogenic material can be found on the surface. To the benefit of analogue studies for Mars exploration, the desert visually resembles Mars as seen through rover cameras. For these reasons: aridity, ultraviolet radiation and soil composition we believe the Atacama is analogous to Mars and an excellent location for rover field experiments. To support our astrobiologic investigation, we have created a mobile robot, Zo‰, that makes the measurement of the distribution and diversity of microorganisms possible. Mobility is crucial as habitats are hypothesized to depend on locally variable conditions including moisture, solar flux, and rock/soil composition. The ability to traverse tens to hundreds of kilometers while deploying sensors is a fundamental requirement because only by visiting many sites will the few in which organisms exist be found. Many observations provide the basis for statistically valid analysis of distribution. Zo‰'s instrument payload combines complementary elements, some directed towards remote sensing of the environment (geology, morphology, mineralogy, climate) for the detection of conditions favorable to terrestrial life and some directed toward the in situ detection of life's signatures (biological and physical, such as biological constructs and patterns). The payload is designed to both detect organic biomarkers, including DNA, carbohydrates, lipids, and proteins, and to characterize habitats. The existence of endoliths in extreme environments similar to early Mars makes the testing of detection methods for chlorophyll-based life a valid working hypothesis. Whether or not life on Mars (if any) used-or uses-photosynthesis, detecting its signature will likely involve accessing isolated oases scattered over large distances. LITA is demonstrating this capability in a relevant terrestrial analogue. In our first field season (2003) we found that microhabitats, on the scale of a few meters or tens of meters, were sparsely distributed in coastal regions and were detectable by fluorescent and spectral signatures. In our second season (2004) Zo‰ revisited the coastal region and also investigated the existence and character of habitats in the desert core. In the third field season (2005), with our astrobiology payload fully functional and operational procedures established, the rover is collecting measurements that provide the basis for a map of life in local areas. Our goal is to make genuine discoveries about the limits of life on Earth and to generate knowledge about life in extreme environments that can be applied to future planetary missions. Through these experiments we also hope to develop and practice the methods by which a rover might best be employed to survey desert terrain and seek evidence of life.
DE: 0424 Biosignatures and proxies
DE: 0452 Instruments and techniques
DE: 0456 Life in extreme environments
DE: 5200 PLANETARY SCIENCES: ASTROBIOLOGY
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: Fall Meeting 2005