Exploring, Mapping, and Data Management Integration of Habitable Environments in Astrobiology

Abstract

New approaches to blending geoscience, planetary science, microbiology-geobiology/ecology, geoinformatics and cyberinfrastructure technology disciplines in a holistic effort can be transformative to astrobiology explorations. Over the last two decades, overwhelming orbital evidence has confirmed the abundance of authigenic (in situ, formed in place) minerals on Mars. On Earth, environments where authigenic minerals form provide a substrate for the preservation of microbial life. Similarly, extraterrestrial life is likely to be preserved where crustal minerals can record and preserve the biochemical mechanisms (i.e., biosignatures). The search for astrobiological evidence on Mars has focused on identifying past or present habitable environments - places that could support some semblance of life. Thus, authigenic minerals represent a promising habitable environment where extraterrestrial life could be recorded and potentially preserved over geologic time scales. Astrobiology research necessarily takes place over vastly different scales; from molecules to viruses and microbes to those of satellites and solar system exploration, but the differing scales of analyses are rarely connected quantitatively. The mismatch between the scales of these observations- from the macro- satellite mineralogical observations to the micro- microbial observations- limits the applicability of our astrobiological understanding as we search for records of life beyond Earth. Each-scale observation requires knowledge of the geologic context and the environmental parameters important for assessing habitability. Exploration efforts to search for extraterrestrial life should attempt to quantify both the geospatial context and the temporal/spatial relationships between microbial abundance and diversity within authigenic minerals at multiple scales, while assimilating resolutions from satellite observations to field measurements to microscopic analyses. Statistical measures, computer vision, and the geospatial synergy of Geographic Information Systems (GIS), can allow analyses of objective data-driven methods to locate, map, and predict where the "sweet spots" of habitable environments occur at multiple scales. This approach of science information architecture or an "Astrobiology Information System" can provide the necessary maps to guide researchers to discoveries via testing, visualizing, documenting, and collaborating on significant data relationships that will advance explorations for evidence of life in our solar system and beyond.

Keywords: Mars; astrobiology; authigenic minerals; cybertechnology; data management; habitable environments.

FIGURE 1

Scientific efforts to explore for biosignatures must link themes of habitability, preservation, and detection of biosignatures. The best potential for exploration targets lies at the intersection of science studies, and data-enabled cyberinfrastructure technology that can provide multi-scale data management and visualization.

FIGURE 2

Examples of morphological biosignatures within authigenic mineral systems identified on Mars. (A) Hematite (red) in Meridiani Planum region detected by TES (after Christensen et al., 2000). (B) Sulfate (red) in the polar dunes detected by OMEGA (NASA/JPL-Caltech/JHUAPL/Brown University). (C) Carbonate-bearing units (green) in Nili Fossae region detected by CRISM (Ehlmann et al., 2008). (D) Phyllosilicate clays (bright colors) associated with delta deposit at Jezero crater detected by CRISM (NASA/JPL/JHUAPL/MSSS/Brown University). (E) Hematite concretions at Eagle Crater, Opportunity (NASA/JPL/USGS). (F) Sulfate-cemented sandstone at Endurance Crater, Opportunity (NASA/JPL/Cornell). (G) Carbonate-containing outcrops, Spirit (NASA/JPL-Caltch/Cornell) (Morris et al., 2010). (H) Clay-rich mudstone and sandstone at Yellowknife Bay, Curiosity (NASA/JPL-Caltech/MSSS). (I) Hematite concretions from the Jurassic Navajo Sandstone (Chan et al., 2004, 2005). (J) Gypsum sand grains from dunes surrounding acid saline lakes in Western Australia. (K) Carbonate stromatolite from the Eocene Green River Formation. (L) Clay bed (kaolinite and halloysite) from acid saline lake sediments. (M) Algal/fungal filaments within 2.1 million year old iron oxide precipitates at Rio Tinto in Spain (Fernández-Remolar and Knoll, 2008). (N) Microbial remnants within gypsum crystal in Western Australia (Benison et al., 2008). (O) Stromatolite laminae from the Green River Formation with quartz grains trapped at high angle of dip indicating the former presence of sticky microbial mat. (P) Bacteria lined with clay minerals from tephra in Hawaii (Leveille and Konhauser, 2007).

FIGURE 3

Microbial analysis is typically characterized in the field context with sample collection (left), for further analyses and culturing in the laboratory leading to the eventual biosignature detection (right). Currently, modern environmental samples are more conducive to biosignature detection than ancient samples that lack good preservation of DNA.

FIGURE 4

Microscopic Imager (MI) mosaics of abraded rocks in the Karatepe stratigraphic section in Endurance crater, Meridiani Planum, Mars. Three color Pancam composite images show overview of the stratigraphic section with locations of MI mosaics (inset images) indicated by dashed green lines (Herkenhoff et al., 2004). Endurance crater is the only site to host all types of secondary pores observed (Perl and McLennan, 2008). Letter notations match the Burns formation schematic of Grotzinger et al. (2005).

FIGURE 5

An integrative AIS looks toward predictive power for futures missions to map habitable environments and find the “sweet spots” of biosignatures through (1) the infusion of geologic and biologic characterizations at multiple scales with (2) statistical measures and a visualization platform.

FIGURE 6

Conceptual illustration of integration of geo-registered datasets at Victoria Crater on Mars to produce map overlays indicating the probability of target variables driving exploration and sampling decisions. In the panel at right, cool colors indicate higher probability of discovering exposed authigenic minerals at that location. Crater diameter ∼800 m across. HIRISE Credit: NASA/JPL/University of Arizona. CRISM Credit: NASA/JPL/JHUAPL.

FIGURE 7

Conceptual AIS data system architecture that could integrate user workflow and astrobiologic data and spatial context across multiple scales.