RESEARCH & PROJECTS
Laboratory for Agnostic Biosignatures
Eric V Anslyn, Pan Conrad, Lee Cronin, Andrew Ellington, Jamie Elsila Cook, Pete Girguis, Chris House, Chris Kempes, Eric Libby, Paul Mahaffy, Jay Nadeau, Barbara Sherwood Lollar, Andrew Steele, Anais Roussel, Andrew Hyde, Tyler Garvin, Geoff Cooper, Lingyu Zeng, Arda Gulay, Béatrice Leydier, Xiang Li, Andrej Grubisic, Jeffrey Marlow, William B Brinckerhoff, Matthew Fricke, Melanie Moses
LAB’s initial research focuses on four features of life that do not presuppose a specific biochemistry, using these concepts to begin to build a framework for looking for life “as we don’t know it.” These features include patterns of surface complexity, elemental accumulation, and evidence of energy transfer. These indicators of life were chosen since they can be framed in a way that doesn’t bias observations toward the specific forms of life on Earth and are approaches that could be implemented on flight missions. Pulling these concepts together, LAB also supports a computational team developing probabilistic and theoretical models to understand the full possibility space for life and a curation group responsible for designing tests and compiling results in a model that can be used to guide sample and instrument selection for future life detection missions.
Oceans Across Time and Space (OAST)
PI: BRITNEY SCHMIDT
Jeff Bowman, Doug Bartlett, Cristopher Carr, Anne Dekas, Peter Doran, Jennifer Glass, Ellery Ingall, Alison Olcott Marshall, Alexandra Pontefract, Christopher Reinhard, Krista Soderlund, Sanjoy Som, Frank Stewart, Amanda Stockton, James Wray, Joseph Levy, Greg Rouse, Craig Marshall, Chris Bennett, John Moores, Ray Jayawardhana, Tim Lyons, Natalie Robinson, Craig Stevens, Mike Williams, Inga Smith, Justin Lawrence, Jacob Buffo
Center for Life Detection Science (CLDS)
PI: TORI HOEHLER
Lee Bebout, Will Brinckerhoff, Chris Dateo, Alfonso Davila, David Des Marais, Jen Eigenbrode, Craig Everroad, Stephanie Getty, Danny Glavin, Linda Jahnke, Barbara Lafuente Valverde, Owen Lehmer,Paul Mahaffy, Niki Parenteau, Andrew Porhille, Richard Quinn, Andro Rios, Sanjoy Som, Mary Beth Wilhelm
Biosignatures of the 'Dirty Ice' of the McMurdo Ice Shelf: Analogues for biological oases during the Cryogenian and on other icy world
PI: ROGER SUMMONS
We seek to characterize the molecular and isotopic biosignatures of microbial ecosystems of the Dirty Ice environments of the McMurdo Ice Shelf (MIS) of Antarctica. These are little-studied melt-water ponds, protected from anthropogenic disturbance and with unique environmental constraints. They are near to freezing even in summer, have diverse chemistries, waters of mixed origin and an unusual light regime. They are also oases of microbial biodiversity in a landscape that is otherwise largely lacking liquid water and poorly supportive of life. The primary objectives of our research are to characterize the biosignatures of a suite of MIS ponds, and to determine which have the potential to be predictive for analog environments. These data will inform studies of a variety of ice-bound ecosystems, potentially including those of icy moons. Moreover, the physiography of the McMurdo Dirty Ice system is such that similar environments were likely widespread during the Cryogenian (720 to 635 Ma). The biosignatures we identify could thus have particular impact on our understanding of the persistence and evolution of life through the Snowball Earth glaciations.
Chlorophyll d as a model for biosignature evolution
PI: WESLEY SWINGLEY
Nancy Kiang, Niki Parenteau, Min Chen, Robert Blankenship
My team is investigating the lower energy limits for oxygen production via photosynthesis as a means of understanding how similar processes may occur on bodies orbiting other, cooler stars. On Earth, far-red light is the lowest solar energy level that can power oxygen production due to energy limits on the oxidation of water to molecular oxygen. As this reaction has been crucial for the development of advanced life on our planet, understanding the energetic limitations of its production is a key component of modeling exoplanet atmospheres for signs of life. Our team is studying the model far-red oxygenic phototroph, the cyanobacterium Acaryochloris, to understand these energy limits, both in context of life around other stars and the history of life on our planet. While it appears this extreme boundary-pushing method of photosynthesis may be a recent invention in our biosphere, it is likely that life on planets and moons orbiting red M dwarf stars (the most abundant in our galaxy) would be driven to these extremes in order to produce oxygenic biospheres.
Exploring destruction of biomolecules in Martian rocks and regolith by Cosmic Rays
PI: ALEXANDER PAVLOV
Based on the recent results from the MSL and Phoenix missions, the Martian shallow subsurface should be considered as the prime candidate to search for the extraterrestrial biosphere both extinct and extant. Therefore, it is critical to understand the preservation of various biomolecules in the Martian shallow subsurface. Recent experiments and modeling work suggest that long-term exposure to Cosmic Rays (CRs) can destroy organic molecules in the top 2 meters of the Martian surface effectively. MSL and Phoenix also found the ubiquitous presence of perchlorate salts in both surface rocks and regolith. CRs interaction with perchlorates will produce additional oxidants in regolith and rocks and likely further increase the rate of destruction of biomolecules on Mars.
We propose to determine the destruction rates of amino acids and peptides in Martian surface rocks and regolith due to long-term exposure to CRs through both laboratory simulations and numerical modeling. Specifically, we will determine the destruction rates of amino acids and peptides in mineral powders mixed with perchlorates and exposed to gamma, neutron and proton radiation. Experimentally derived radiolysis constants will be then used in conjunction with the Monte Carlo computer code to determine the destruction rates of amino acids and peptides at various depths and during various epochs on Mars.
Investigating a novel role for iron redox cycling in the lithification of microbial mats and the rise and fall of stromatolites in Earth history
PI: FRANK CORSETTI
Stromatolites laminated, lithified structures typically built by microbial mats represent the most abundant record of life in the first 7/8ths of Earth history (the Archean and Proterozoic Eons). As macroscopic manifestations of microbial life, they represent a clear target for exobiologic investigation. Despite a long history of study, many strikingly fundamental questions remain with respect to stromatolite formation and their distribution throughout geologic time. Two pertinent questions include: 1) How do microbial mats lithify to become stromatolites (i.e., rocks)? It is still not clear how soft, organic-rich microbial mats transform into hard, lithified stromatolites. 2) What controlled the distribution of stromatolites through time? Stromatolites reached a form diversity peak ca. 1.0 billion years ago, crashed, and became comparatively rare throughout the remaining 600 million years of Earth history. The most common hypothesis the evolution of burrowing/grazing metazoans disrupting the microbial mats is not tenable, as the decline initiated well before the advent of animals.
Here, we propose to investigate how the redox cycling of iron, not previously considered important for the formation of stromatolites, may lead to the lithification of soft microbial mats, and how the changes in the dissolved iron in Archean, Proterozoic, and Phanerozoic oceans may link to the decline in stromatolite abundance and form diversity well before the evolution of animals.
Mapping X-ray Fluorescence Spectrometer (MapX)
PI: DAVID BLAKE
Thomas Bristow, Robert Downs, Marc Gailhanou, Franck Marchis, Douglas Ming, Richard Morris, Philippe Sarrazin, Vincent Armando Sole, Kathleen Thompson, Philippe Walter, Michael Wilson, Albert Yen, Samuel Webb, Richard Walroth
MapX will provide elemental imaging at ≤100 μm spatial resolution over 2.5 X 2.5 cm areas, yielding elemental chemistry at or below the scale length where many relict physical, chemical, and biological features can be imaged and interpreted in ancient rocks. MapX is a full-frame spectroscopic imager positioned on soil or regolith with touch sensors. During an analysis, an X- ray source (tube or radioisotope) bombards the sample surface with X-rays or α-particles / γ-rays, resulting in sample X-ray Fluorescence (XRF). Fluoresced X-rays pass through an X-ray lens (X-ray μ-Pore Optic, “MPO”) that projects a spatially resolved image of the X-rays onto a CCD. The CCD is operated in single photon counting mode so that the positions and energies of individual photons are retained. In a single analysis, several thousand frames are stored and processed. A MapX experiment provides elemental maps having a spatial resolution of ≤100 μm and quantitative XRF spectra from Regions of Interest (ROI) 2 cm ≤ x ≤ 100 μm. ROI are compared with known rock and mineral compositions to extrapolate the data to rock types and putative mineralogies.
The MapX geometry is being refined with ray-tracing simulations and with synchrotron experiments at SLAC. Source requirements are being determined through Monte Carlo modeling and experiment using XMIMSIM , GEANT4  and PyMca  and a dedicated XRF test fixture. A flow-down of requirements for both tube and radioisotope sources is being developed from these experiments. In addition to Mars lander and rover missions, MapX could be used for landed science on other airless bodies (Phobos/Deimos, Comet nucleus, asteroids, the Earth’s moon, and the icy satellites of the outer planets, including Europa.
Exceptional preservation of Ediacaran organic biosignatures yields novel insights into the marine environments and ecology that hosted early multicellular organisms
PI: GORDON LOVE
Andrey Bekker, Carina Lee, Kelden Pehr, Adam Hoffmann, Nathan Marshall, Adriana Rizzo
The main goal of my research program is understanding the production, alteration and preservation of organic (carbon-based) molecules on Earth over geologic time to track the evolution of life and surface planetary environmental change. This organic matter was produced predominantly by biological organisms, which were exclusively unicellular microbes confined to aquatic environments for a large proportion of the 4.6 Gyr history of our planet during the Precambrian (>541 Myr. I use state-of-the-art chemical techniques for analyzing individual organic compounds found in ancient sedimentary rocks, oils and meteorites and apply a range of complementary stable isotope and inorganic geochemical approaches for understanding carbon and other element biogeochemical cycling in the modern and ancient biosphere.
I have continued to use and refine novel analytical approaches that I helped develop to address topical issues in geobiology, astrobiology and organic geochemistry. My broad research program encompasses formulating strategies for detecting robust molecular biosignatures preserved in the sedimentary record across the breadth of geological time; including tracking the expansion of the eukaryotic domain of life through the Proterozoic Eon (2500-541 Myr), the appearance of early animals and recording fundamental transitions in planktonic microbial communities with changing oceanic redox chemistry through major extinction events in the Paleozoic era. My research group looks in detail at the variety and abundance of the biomarker pool preserved by being covalently linked into geomacromolecules (such as kerogen), and we have developed sensitive analytical methods for analysis of these bound biomarker compounds.
Toward Geophysical Detection of the Biological Modification of Ice
PI: DAVID STILLMAN
Microorganisms found in glaciers, sea ice and permafrost can remain viable, or even metabolically active, at temperatures well below 0°C. These organisms can live within the salty liquid-vein networks that exist between ice crystals. In this proposal, we will study the extracellular ice binding protein (IBP) that inhibits ice recrystallization from cold-tolerant microorganisms isolated from the basal ice of an Antarctic ice core. Similar extant life could exist within warm pockets of Europa s ice shell (chaos terrain). Using magnetic resonance (MR) techniques, we have previously shown that this IBP drastically alters liquid-vein networks within ice. Using dielectric spectroscopy (DS) measurements, we have previously shown on recrystallized IBP-free ice that the dielectric properties of ice are dominated by liquid-vein networks.
In this proposal, these two laboratory techniques will conduct measurements on the same samples combining MR diffusion measurements with measurements of the electrical properties for the first time on ice. MR techniques and simple microscopy conducted at Montana State University will provide us with microstructural properties (unfrozen water content, ice-grain size, surface-area-to-volume-ratio, diameter of liquid veins and tortuosity) and imagery of triple junction liquid networks. DS measurements conducted at Southwest Research Institute in Boulder will provide us with broadband complex electrical properties, which can be used to determine the likelihood of a remote geophysical detection of IBP. We will study the detectably of two geophysical techniques (ice penetrating radar and magnetotellurics) that can measure variations of the electrical properties of Europa s ice shell. This project will constitute the first time that MR techniques and DS have been used together to study the microstructural and electrical properties of an icy microbial habitat altered by a biosignature (IBP).
Biosignature Preservation in Sulfate-Dominated Hypersaline Environments
Magdalena Osburn, Christopher Carr, Jack Szostak, Shuhei Ono, Virgnia Walker
This research focuses on developing a comprehensive understanding of a hypersaline, Mars analog environment, addressing the central question: “What types of biosignatures form and are preserved over time?” We are addressing this question specifically in a magnesium sulfate dominated system as sulfate salts have been widely documented on Mars, but are not the dominant type here on Earth. Here we focus on understanding four different biosignatures, each with varying residency times in the geologic record: DNA, amino acids, lipids and sulfur isotopic fractionation signatures. Salt has a documented ability to preserve biological molecules over longer timescales than non-saline environments, and whole cells have been preserved in a viable state within fluid inclusions on the order of thousands of years. The field site is located in and around Clinton, British Columbia, Canada. Currently our team is working on the Basque Lakes, Last Chance Lake and Salt Lake.
SLICE Spectral Signs of Life in Ice
Marco Tedesco and Shujie Wang, Lamont-Doherty Earth Observatory, Columbia University
Christine Foreman, Markus Dieser, Heidi Smith and Mitch Messmer, Montana State University
Identifying life on other planets is one of the most exciting challenges of our times. The Earth's Polar Regions have long been recognized among the best terrestrial analogs for conditions on Mars, with cryoconite holes being one of the proposed habitats for life on other planets. Cryoconite holes are mini-entrained ecosystems, found in the ablation zone of glaciers that provide conditions by which subsurface liquid water can exist in spite of otherwise hostile environmental conditions.Â
One of the tools in the search for life has been the collection and interpretation of hyperspectral images; however the validation of reliable biomarkers in this data remains ongoing. The hyperspectral and associated measurements collected by SLICE are being used to support the analysis of data collected by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), the OMEGA spectrometer on the Mars Express ESA mission and the THEMIS instrument on the MARS Odyssey mission. By studying the terrestrial analogs of cryoconite holes, we are isolating and culturing cryoconite organisms, determining their spectral signatures through in-situ and laboratory hyperspectral measurements and developing a spectral library of biosignatures. In this context, cryoconite holes represent a unique environment on Earth that resembles life on Mars. Consequently, our project directly addresses several of the main program elements of the new Astrobiology Strategy (2015) namely, early life and increasing complexity, co-evolution of life and the physical environment and identifying, exploring, and characterizing environments for habitability and biosignatures.
In-situ Vent Analysis Divebot for Exobiology Research (InVADER)
PI: PABLO SOBRON
Tayro Acosta-Maeda, Jan Amend, Laurie Barge, Justin Burnett, Renaud Detry, Ivria Doloboff, Ninos Hermis, Deborah Kelley, Dana Manalang, Aaron Margburg, Anupam Misra, Anuscheh Nawaz, Roy Price, Fredrik Rehnmark, Marianne Smith, Pablo Sobron, Blair Thornton, David Yu, Kris Zacny
InVADER will study underwater hydrothermal systems at Axial Seamount, the largest and most active volcano on western boundary of the Juan de Fuca tectonic plate off the coast of Oregon. The vents at the Axial Seamount generate chemical energy which can sustain life, and are high- fidelity analogues to putative vent systems on Ocean Worlds.
InVADER will integrate a payload containing 3D visual mapping and LRS/LIBS/LINF technologies into a divebot. This payload will enable standoff determinations of: a) relevant disequilibria in vent systems, b) composition and mineralogy of hydrothermal chimneys and associated precipitates, c) relevant small-scale features that are indicators of vent geochemistry and/or habitability, and d) the presence and distribution of organics. Thus, the project is relevant to PSTAR's overarching objectives and addresses multiple areas of Science, Technology, and Science Operations fidelity.
Miniaturized Inductively Coupled Plasma Mass Spectrometer (ICPMS) for Trace Element Analysis
PI: RICARDO AREVALO
Ben Farcy, William McDonough, Mazdak Taghioskoui, Mehdi Benna, William Brinckerhoff, Grace Ni
Trace elements, which are defined by abundances of <1000 ppmw in geological materials, serve as extraordinarily sensitive tracers of a variety of planetary processes including (but not limited to): i) biomineralization; ii) meteoritic infall (i.e., source of exogenous organic compounds); iii) hydrothermal activity and/or aqueous alteration; iv) weathering, erosion and sedimentation; and, v) magmatism, which in turn reflects local pressure, temperature and redox conditions in planetary interiors. In the commercial realm, trace elements are most commonly measured via inductively coupled plasma mass spectrometry (ICPMS) techniques, where a high-temperature (10,000 K) plasma effectively serves to atomize and ionize both solid (e.g., crystalline minerals or amorphous glasses) and liquid materials (e.g., water samples or chemical extracts). However, traditional modes of in situ chemical analysis available for planetary exploration, such as laser desorption mass spectrometry (LDMS; e.g., the MOMA investigation on the ExoMars rover) and laser-induced breakdown spectroscopy (LIBS; e.g., ChemCam on the Curiosity rover), are challenged to meet the limits-of-detection that enable the accurate quantitation of trace element abundances.
The Thermal Maturity of Neoproterozoic Strata: Carbonate Clumped Isotope Thermometry and Biomarker Analyses
PI: KRISTIN BERGMANN
Tyler Mackey, Julia Wilcots, Marjorie Cantine, Noah Anderson
The Neoproterozoic Era (541-1000 Ma) was a transitional time in the history of life that included both the emergence of early animals and other complex eukaryotes in the midst of Cryogenian climate perturbations (635-850 Ma). However, the specifics of both the climate record and the evolutionary tempo of eukaryotic diversification remain poorly resolved. First, multiple aspects of the climate record could be better known. Perhaps most importantly, temperature constraints across the background climate and before, during and after the 'snowball earth' glacial perturbations will address decades long uncertainties about the Precambrian climate. Second, while great strides have occurred with the fossil and biomarker record of life, high resolution records to define the tempo of evolution are rare. We propose a holistic study of the thermal maturity of shallowly buried Neoproterozoic strata globally to assess the best sites able to provide a paired high resolution clumped isotope and biomarker record through the Neoproterozoic.
The Enceladus Organic Analyzer (EOA)
PI: RICHARD MATHIES
Anna Butterwirth, Amanda Stockton, Jungkyu Kim, James New, Matin Golozar
Mathies' work in the area of analytical chemistry, biotechnology and the Human Genome Project led to the development of new high-speed, high-throughput DNA analysis technologies such as capillary array electrophoresis and energy transfer (ET) fluorescent dye labels for DNA sequencing and analysis. In particular, his development of ET fluorescent labels was a critical contribution to the early completion of the Human Genome sequence. He also pioneered the development of microfabricated capillary electrophoresis devices and microfabricated integrated sample preparation and detection methods for lab-on-a-chip analysis systems that are being applied to DNA sequencing, diagnostics, forensics, pathogen detection and space exploration. The combination of high sensitivity laser-induced fluorescence detection and microfabricated capillary electrophoresis led to the development of the Mars Organic Analyzer prototype. This instrument provides part-per-billion sensitivity for the detection of organic amines, amino acids, aldehydes, ketones, organic acids and polycyclic aromatic hydrocarbons in solar system exploration. The MOA prototype has also been used to demonstrate that amino acids and dipeptides are synthesized in model interstellar ices through simulated galactic cosmic ray irradiation. Coupled with integrated microfluidic sample processing, this instrument is the basis for pending proposals to chemically explore icy moons including Enceladus (Saturn) and Europa (Jupiter) for extraterrestrial life.
fs-LDPI MS mapping of organic compounds in deep time Earth sediments: A tool for determination of the spatial distribution of lipid biosignatures at the micron scale
PI: FABIEN KENIG
Luke Hanley, Joey Pasterski, Raveendra C. Wickramasinghe
The UIC Organic Geochemistry group focuses on means to separate potential earth molecular biosignatures and potential astrobiological molecular signals of life. For the first project, I am developing with collaborator Luke Hanley (Department of Chemistry, UIC) and my Graduate student Joey Pasterski, the use of a prototype laser desorption-laser ionization-mass spectrometer capable of mapping and depth profiling organic compounds in rocks at the micron scale. Such an approach allows for the observation of organic compounds within their mineral matrix and to better assess their origins, including contaminations. Our group, in collaboration with D'Arcy Meyer-Dombard (Department of Earth and environmental sciences, UIC) also focuses on understanding the effects of life at very high pressure on membrane lipids. This project seeks to determine unambiguous targets for life detection in the high-pressure oceans of Jovian satellites, especially Titan. Finally, our group is interested in separating the information provided by molecular biosignatures derived from a current ecosystem from those provided by legacy biosignatures derived from past ecosystems that occupied the same environment. Such an approach, led by Graduate student Luoth Chou, may allow for the distinction between life versus past life biosignatures in an astrobiological context.
Preservation and detection of extremophiles in Mars-analog halite and gypsum
PI: KATHLEEN BENISON
Anna Sofia Andeskie
Many sediments and sedimentary rocks on Mars have similar mineral assemblages, sedimentary characteristics, and diagenetic features as modern and ancient red bed and evaporite sequences on Earth. Acid brine lake systems on cratonic rocks in Western Australia and at an active volcanic complex in northern Chile have pHs as low as 1.4, salinities up to 10 times saltier than seawater, complex aqueous compositions, and precipitate halite, gypsum, iron oxides, alunite, jarosite, opalline silica, and clay minerals. Despite extreme chemistry and low water activity, recent and ongoing studies have documented diverse communities of extremophilic microorganisms, many of which are novel, living in these acid brine lake waters and groundwaters. Are these microorganisms preserved in the mineral and rock record here? Preliminary investigation suggests that the rapid growth of minerals from acid brines causes halite and gypsum to trap microorganisms and organic compounds as solid inclusions and within fluid inclusions. However, further study is needed to fully identify the modes of preservation of biological material, as well as test and refine detection methods. The primary goal of this proposed research is to use microscopy and spectroscopy to characterize the microbial community preserved within halite and gypsum from modern acid brine lakes in Western Australia and Chile. Secondary goals of the project include: (1) investigating Permo-Triassic (~250 Ma) acid lake halite and gypsum for any preserved microorganisms and/or organic compounds; (2) documenting the preservation mode in relation to in situ or reworked halite and/or gypsum, as well as the role of associated iron oxide and/or clay mineral coatings; and (3) comparing biological matter in modern and ancient acid lake halite and gypsum to evaluate whether microbes and organic compounds can remain preserved through deep time.
SELFI (Submillimeter Enceladus Life Fundamentals Instrument)
PI: GORDON CHIN
Carie Anderson, Damon Bradley, Terry Hurford, Tilak Hewagama, Tim Livengood, Paul Racette, ,Karen Junge
SELFI (Submillimeter Enceladus Life Fundamentals Instrument) will diagnose the composition of the Enceladus subsurface ocean as entrained by its plumes and decipher its history and current environment. SELFI uses submillimeter heterodyne spectroscopy to remotely observe 14 molecular species simultaneously that are important in the context of life and habitability entrained by the Enceladus plumes that sample the subsurface ocean (including five, colored green, of the six CHNOPS elements necessary for life). SELFI can be adapted to explore other Solar System targets.
Using Proteome Dynamics of Psychrophilic Bacteria to Decipher Metabolic Strategies and Protein Signatures Indicative of Sustained Life in Ice
PIs: BROOK NUNN, KAREN JUNGE
Karen Junge, Bonnie Light, Brook Nunn, Marcella Ewart Sarmiento, Jonathon Toner
Icy worlds are key targets for astrobiology because of their potential to harbor liquid water. On Mars, possible occurrences of near-surface liquid water are widely believed to be brine-rich aqueous flows. Enceladus, Europa, and possibly Pluto are thought to contain large saline oceans beneath kilometers-thick ice covers, and, on Earth, microbial habitats in polar and glaciated regions are found in brine-rich sea ice matrices and glacial veins and inclusions. Throughout its history, Earth has experienced global glaciations (so called “Snowball Earth” events) with life presumably surviving in refugia. Such protected environments may have been in brine, which remains liquid at subzero temperatures. Recent studies have contributed greatly to our understanding of low-temperature biology and extended the lower temperature limits for life. Bacteria that are growing, metabolically active, and surviving in low-temperature environments may have characteristics that reflect the evolution and physiological adaptations required for life to survive in such conditions. Detection of these characteristics may hold answers to questions about the origin, evolution, and ultimate fate of microbial cells and their biosignatures.
Detecting the fundamental chiral building blocks of life
PI: WILLIAM SPARKS
We propose to expand our exploration of the rich diversity of chiral signatures, which we have already begun in the visible for photosynthetic organisms, into the UV. This focused, pilot program will identify and characterize chiral spectral transitions in the UV of relevant biotic and abiotic samples, intended to lead to a capability for critical diagnostic support for missions searching for life beyond Earth. These agnostic chiral biosignatures are present in the circular polarization spectrum, which may be obtained for both in situ and remote sensing applications.
Gypsum-hosted biosignatures in subterranean chemosynthetic ecosystems
PI: DANIEL JONES
Heather Graham, Jennifer Stern, Scott Wankel
Gypsum and other hydrated sulfate minerals are widespread on the surface of Mars, and are considered promising targets for the detection of past and potentially present Martian life. However, the timescales, nature and fidelity of biosignature preservation in gypsum are poorly understood. In order to evaluate gypsum as a target for biomarker detection on Mars and other extraterrestrial bodies, we need to evaluate how signatures of life are recorded in gypsum deposits on our home planet.
We propose to take advantage of an exceptional natural experiment in Earth s subsurface to develop and evaluate gypsum-hosted biosignatures associated with microbial chemosynthesis. In sulfidic limestone caves, gypsum deposits form by sulfuric acid corrosion. Initially, gypsum forms as wall residues, coated by acidophilic sulfide- oxidizing microbial communities. These gypsum wall crusts later accumulate on the floor as they thicken and slump to the ground. Gypsum floor deposits can be preserved for millions of years in sulfidic caves, and likely record organic material and other evidence from the extremophilic communities that were present during initial mineral precipitation.
Developing Methane Isotopologues as Interplanetary Biosignatures
PI: EDWARD YOUNG
We will conduct a program of experiments to evaluate the potential of methane clumped isotope ratios as geochemical and biogeochemical tracers for solar system bodies in general. Multiply substituted isotopologues of methane are well suited as tracers of methane formation pathways in general, and potential biosignatures in particular. They remove the difficulties associated with using bulk carbon and hydrogen isotope ratios on other worlds where the geochemical context necessary for interpreting these ratios are by necessity lacking. However, uncertainties remain about the uniqueness of the isotopologue signatures. We will conduct experiments that will mitigate these uncertainties. Our work will inform future missions about the potential benefits of including in-situ measurements of rare methane isotopologues on Mars, Enceladus, and other bodies where the origin of methane is a key geochemical and biogeochemical tracer.
Ultra-Violet Detector Innovation for Raman Exploration and CharacTerization (UV-DIRECT) of Ocean Worlds
PI: DINA M. BOWER
Shahid Aslam, Tilak Hewagama, Nicolas Gorius, Anand Sampath, Jonathan Schuster
UV-DIRECT enables the identification of minerals, volatiles, organic molecules, biopolymers, water, and other hydrous phases to assess habitability and detect signatures of life in ocean world environments. UV-DIRECT encompasses the development of a compact, energy efficient, ruggedized linear detector array that is impervious to visible light with ppb sensitivity for in situ surface exploration using UV Raman spectroscopy.
Cold and dry limit to life: Understanding microbial activity in dry permafrost samples from the newly discovered Elephants Head, Antarctica
Our goal is to investigate a newly discovered dry permafrost location at Elephant's Head, Antarctica to understand whether cold and dry permafrost represents a natural limit to life on Earth, or whether the results at University Valley, Antarctica are unique. Our objectives are to (1) detect present day biological activity and (2) look for evidence of past activity to understand the preservation potential of biosignatures in dry permafrost and underlying ice cemented permafrost soils.
How Microbes Adapt to Living in the Upper Atmosphere: Implications for Cloud Formation, and Life During Early Earth and Elsewhere in the Universe
The abundance of microorganisms in the atmosphere can be high enough to absorb solar radiation and modulate the formation and chemical processes in clouds, thereby affecting the hydrological cycle and climate. Several bacterial species are known to serve as efficient ice nuclei based on an excreted protein (InaZ) that can initiate the formation of ice at temperatures as high as -4°C and thus, potentially participate in cloud formation in the atmosphere. Beyond this, very little quantitative understanding exists on the efficiency of ice nuclei (IN) or cloud condensation nuclei (CCN; when ambient temperature is above the freezing point) formation by different microbial species and more importantly, which cell properties control the observed CCN/IN activity. Yet, condensing water vapors around the cell (i.e., CCN activity) was probably one of the very first cellular functions that enabled life during the early history of (hot) Earth. Therefore, identifying these cellular properties and corresponding proteins, and studying their phylogenetic distribution in the tree of life, e.g., how ancestral such proteins may be, may provide new insights into early life. Further, how the physiology and CCN/IN activity of a cell changes during environmental transition (e.g., increasing temperatures, greenhouse gases and UV) also remains essentially unknown; yet, these cellular adaptations are presumably important for successful survival in the atmosphere and during climate change as well as for survival in the hot and gaseous primordial soup. How life adapts to living in the atmosphere is not only relevant for early life and bioaerosol-cloud-precipitation-climate interactions but, more importantly, for Exobiology as the atmosphere is one of the most extreme environments on our planet and a good analog for airborne life elsewhere.
This project will address these issues by studying the CCN/IN activities of different cell types collected from the atmosphere under changing environmental conditions using the advanced instrumentation that we recently developed to measure these activities. Following these laboratory experiments, we will leverage a plethora of archived samples collected on board specialized NASA aircrafts to test our findings from the laboratory in-situ, using culture-independent techniques such as metagenomics (DNA level, who is there) and metatranscriptomics (what gene functions they activate). To achieve these goals, a combination of isolate manipulation studies, shotgun metatranscriptomics, and advanced laboratory instrumentation for measuring CCN/IN efficiency of cells will be employed, building upon a substantial body of relevant preliminary results and available infrastructure in the Konstantinidis Lab. The project will provide multifaceted learning experiences for graduate students at the interface of microbiology and genomics with aerosol science and chemistry. This project will contribute to at least one important area of the Exobiology program: (ii) to understand the phylogeny and physiology of microorganisms whose characteristics may reflect the nature of primitive environments.
Targeted Life Detection in Subsurface Serpentinites
PI: ALEXIS TEMPLETON
Eric Boyd, Srishti Kashyap, Tristan Caro, Mason Munro-Ehrlich, Dan Colman, Rachel Spietz, Alexis England
Our project will demonstrate how biological activity is localized in the serpentinite subsurface and further develop a framework for life-detection in fractured rock hosted ecosystems. We will quantify the distribution of microbial activity in serpentinite rock cores spanning geochemical and mineralogical gradients. This work will include experimental measurements of the rates of tritium incorporation into biomass to identify “hot spots” of activity, rates of deuterium incorporation into lipids to quantify turnover times, mineralogical characterization to recognize where and why “hot spots” exist, and rates of C1 compound assimilation/dissimilation to trace some of the dominant metabolic and biosynthetic processes. This focus on microbial activity in serpentinite rocks will then be followed by efforts to determine the metabolic potentials and ongoing diversification of organisms via genomic sequencing. We will also characterize the microbe/mineral transformation processes and feedbacks through chemical and biological imaging approaches.
The Interior Life of Dunes
Michael France, Jani Radebaugh, Ralph Lorenz, Jacques Ravel
Despite extreme temperature swings and paucity of water, desert soils host diverse and active microbial communities that are distinct from other biome soils. Microbes are also found in the top layer of sand dunes, but the habitability of the more benign dune interior has yet to be explored. Understanding the link between the environment and the inhabitants in terrestrial dunes is critical for evaluating the habitability potential of dunes elsewhere in the solar system, especially Mars and Titan, where surface conditions are even more extreme than on Earth. We are conducting in situ investigations at terrestrial dunes to concurrently quantify physical, chemical, and biological characteristics. Comparing these data will provide fundamental new insight into processes and conditions that create and maintain habitable environments, thereby informing the search for such environments beyond Earth.
Europan Molecular Indicators of Life Investigation (EMILI)
Peter Willis, Tony Ricco, Andrej Grubisic, Jennifer Stern, Fernanda Mora, Jessica Creamer, Richard Quinn, Ryan Danell, Kris Zacny, Cyril Szopa
EMILI is a project to develop and demonstrate a prototype and technologies for the Organic Composition Analyzer (OCA) as specified for the Europa Lander mission concept. EMILI combines both derivatization gas chromatography (GC) and capillary electrophoresis/laser induced fluorescence (CE/LIF) separation front ends interfaced to a common ion trap mass spectrometer (ITMS) to provide comprehensive detection and structural characterization of potential molecular biosignatures in cryogenic fines collected by the Lander from the surface of Europa. Funding is provided by the Instrument Concepts for Europa Exploration 2 (ICEE-2) program.