Application of pulsed‐excitation fluorescence imager for daylight detection of sparse life in tests in the Atacama Desert

Abstract

[1] A daylight fluorescence imager was deployed on an autonomous rover, Zoë, to detect life on the surface and shallow subsurface in regions of the Atacama Desert in Chile during field tests between 2003 and 2005. In situ fluorescent measurements were acquired from naturally fluorescing biomolecules such as chlorophyll and from specific fluorescent probes sprayed on the samples, targeting each of the four biological macromolecule classes: DNA, protein, lipid, and carbohydrate. RGB context images were also acquired. Preparatory reagents were applied to enhance the dye probe penetration and fluorescence intensity of chlorophyll. Fluorescence imager data sets from 257 samples were returned to the Life in the Atacama science team. A variety of visible life forms, such as lichens, were detected, and several of the dye probes produced signals from nonphotosynthetic microorganisms.

Fluorescence Characterization of Clinically-Important Bacteria

“…Other prior applications of fluorescence techniques include assessing the presence of organic compounds or pollutants in the environment [16–18], identifying potentially pathogenic or toxic microorganisms in environmental water or food preparation [19–22], and detecting trace concentrations of microorganisms in glacial [23] and Antarctic ice [24], Antarctic sandstone [25], and the Atacama desert [26]. …”

A Microbial Oasis in the Hypersaline Atacama Subsurface Discovered by a Life Detector Chip: Implications for the Search for Life on Mars

“…Gramain et al (2011) described the archaeal community, identified via nested PCR and cultivation, that occupied a pure halite core up to 15 m deep from the Salar Grande. However, most of the microbiological and life-detection studies on the Atacama Desert have focused mainly on the surface or very close to it (Navarro-González et al, 2003;Lester et al, 2007;Weinstein et al, 2008). Cabrol et al (2007) used a fluorescence detection system on board a rover (Zoë) to detect fluorescent signals from biological material (e.g., chlorophyll) along different transects.…”

Life in the Atacama: Science autonomy for improving data quality

“…Finally, the science team used orbital imagery from ASTER [ Abrams , 2000], Hyperion [ Pearlman et al , 2001], and IKONOS [ Dial et al , 2003] as an integral part of planning over‐the‐horizon traverses. Details about science instrument payload are given by Cabrol et al [2007] and Weinstein et al [2007].…”