Dina M Bower

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Dina M Bower

  • Research Scientist
  • 301.614.5786
  • NASA/GSFC
  • Mail Code: 699
  • Greenbelt , MD 20771
  • Employer: UNIV OF MARYLAND COLLEGE PARK
  • Research Interests

    Life detection strategies for ancient Earth rocks and on Mars and Ocean Worlds; Raman spectroscopy for planetary science and the characterization of terrestrial environments; the interactions between microbes and minerals and how these interactions shape the geologic landscape; the evolution of carbon in the solar system; Low-temperature microscopy and spectroscopy; development of hybrid spectroscopic instruments for field work and in situ planetary surface exploration; lunar mineralogy

    Dr. Dina M. Bower uses Raman spectroscopy to geochemically characterize a variety of geologic materials from modern and ancient terrestrial environments, meteorites, lunar regolith, and laboratory synthesized analogs. She has expertise with biosignature detection in ancient Earth rocks that contain microfossils or carbonaceous materials, and experimentally induced biominerals. She also applies her expertise to identifying biosignatures and characterizing the host material characteristics in icy Ocean Worlds analogues. Dr. Bower also develops different types of Raman instrumentation for in situ planetary exploration and tests the utility of portable instruments in analog field sites.

    Brief Bio

    Dr. Dina Bower is an interdisciplinary scientist with a background in marine chemistry and mineralogy. She has focused much of her career on geochemistry and life detection in the context of reconstructing early life on Earth. Dr. Bower has several years of experience utilizing Raman spectroscopy and spectroscopic imaging for in situ field measurements and high-resolution laboratory applications. Her expertise is complemented with the use of other analytic approaches to characterize a wide variety of bio-geologic materials, including microscopy-optical petrography, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), electron probe microanalysis, cathodoluminescence, and reflectance spectroscopy. Dr. Bower applies her knowledge of biogeochemical science requirements and hands on expedition experience to the development of spectroscopic instruments and hybridized systems for field work and planetary missions.

    Current Projects

    The Identification of Biosignatures and Evidence of Habitability in Ocean Worlds Analogues using Raman and Reflectance Spectroscopy

    The ability to identify biosignatures in icy environments is essential for upcoming life detection missions on Europa, Enceladus or other Ocean Worlds. Raman spectroscopy can be used to quickly and efficiently identify minerals, salts, and organics with in situ measurements, and reflectance spectroscopy provides large-sale characterizations of icy environments. Dr. Bower's work couples the two techniques to bridge the gap between remote sensing and in situ measurements. The applications of her work stretch beyond planetary science into oceanography, where Raman facilitates the measurements of salinity, temperature, gas composition, and organics characterization of seawater and sea ice. 

    Instrument Development for in situ Spectroscopy Techniques

    Dr. Bower is working on projects that facilitate the use of Raman spectroscopy for in situ planetary missions, for landers, rovers, or future human-led endeavors. She works on hybrid instrumentation to merge spectroscopic techniques for geochemical measurements as well as spectrometry-spectroscopy instrumentation for combined biochemical-geochemical measurements.

    Geochemical characterization of ancient terrestrial hydrothermal deposits to establish biosignatures for exoplanetary life detection

    Raman spectroscopy is a non-destructive technique that can identify several different chemical species in one scan, and Raman imaging facilitates the visualization of spatial relationships and an understanding of context. Many ancient cherts on Earth contain different types of biosignatures indicative of the earliest forms of life as far back as ~3.5 Ga. Signatures useful for life detection, such as organics, biominerals, and carbon isotopes, are detectable using Raman spectroscopy. With Raman spectroscopy we can reconstruct the geologic history of deposits by characterizing the the chemical composition and structural attributes of mineral phases and fluid inclusions. The data collected from Earth rocks guides mission protocols for upcoming planetary missions.

    To corroberate the Raman results, Dr. Bower also analyzes the same samples using electronprobe microanalysis (EPMA) and microscopy. This provides a better understanding of the sources of some of the more ambiguous mineral assemblages and organics that appear to be indicative of life but are actually abiotic. The combination of EPMA and Raman provides a way to calibrate changes in the Raman spectra with changes in elemental composition, increasing the robustness of Raman spectrscopy.

    Discerning the Origins and Geologic Evolution of Lunar Deposits Using Raman Spectroscopy

    Lunar rocks are composed of a limited suite of minerals, and being able to detect the subtle differences between mineral phases is essential in understaning their origins and evolution. The lunar surface is constantly bombarded by micrometeorites and solar wind, resulting in a dynamic sedimentary environment. Raman spectroscopy provides specific compositional and structural information of mineral phases in lunar regolith and has the potential to identify trapped gases implanted by the solar wind. Dr. Bower has characterized Apollo 16 samples and other lunar simulants, and she is developing methods to detect implanted species using Raman spectroscopy in combination with more traditional methods. This work supports science questions regarding the origins and evolution of lunar regolith, as well as ISRU efforts.

    Publications

    Refereed

    Chan, M. A., N. W. Hinman, S. L. Potter-McIntyre, et al. K. E. Schubert, R. J. Gillams, S. M. Awramik, P. J. Boston, D. M. Bower, D. J. Des Marais, J. D. Farmer, T. Z. Jia, P. L. King, R. M. Hazen, R. J. Leveille, D. Papineau, K. R. Rempfert, M. Sanchez-Roman, J. R. Spear, G. Southam, J. C. Stern, and H. J. Cleaves. 2019. "Deciphering Biosignatures in Planetary Contexts." Astrobiology, 19 (9): 1075-1102 [10.1089/ast.2018.1903]

    Callefo, F., F. Ricardi-Branco, G. Hartmann, et al. D. Galante, F. Rodrigues, L. Maldanis, E. Yokoyama, V. Teixeira, N. Noffke, D. Bower, E. Bullock, A. Braga, J. Coaquira, and M. Fernandes. 2019. "Evaluating iron as a biomarker of rhythmites — An example from the last Paleozoic ice age of Gondwana." Sedimentary Geology, 383: 1-15 [10.1016/j.sedgeo.2019.02.002]

    Bower, D. M., D. R. Hummer, and A. Steele. 2017. "AN EXPERIMENTAL LOOK AT THE TAPHONOMY OF CYANOBACTERIAL MATS IN SILICICLASTIC SEDIMENTS." PALAIOS, 32 (12): 725-738 [10.2110/palo.2017.016]

    Bower, D. M., A. Steele, M. D. Fries, O. R. Green, and J. F. Lindsay. 2016. " Raman imaging spectroscopy of a putative microfossil from the ~3.46 Ga Apex Chert: insights from quartz crystal orientation ." Astrobiology, 16 (2): [10.1089/ast.2014.1207]

    Bower, D. M., D. R. Hummer, A. Kyono, and A. Steele. 2015. "The co-evolution of Fe-,Ti-oxides and other microbially induced mineral precipitates in sandy sediments: understanding the role of cyanobacteria in weathering and early diagenesis ." Journal of Sedimentary Research, 85: 1213-1227 [10.2110/jsr.2015.76]

    Bower, D. M., A. Steele, M. D. Fries, and L. Kater. 2013. "Micro Raman spectroscopic investigations of carbonaceous material in microfossils and meteorites: improving the use of G- and D-band parameters for life detection." Astrobiology, 13 (1): 103-113 [10.1089/ast.2012.0865]

    Szponar, N., W. J. Brazelton, M. O. Schrenk, et al. D. M. Bower, A. Steele, and P. L. Morrill. 2013. "Geochemistry of a continental site of serpentinization in the Tablelands Ophiolite, Gros Morne National Park: a Mars analogue ." Icarus, 224: 286-296 [10.1016/j.icarus.2012.07.004]

    Bower, D. M. 2011. "Micro Raman spectroscopic investigations of laminae associated mineral assemblages in 2.9 Ga sandstones of the Pongola Supergroup, South Africa." Journal of Raman Spectroscopy, 42 (8): 1626-1633 [10.1002/jrs.2903]

    Noffke, N., N. Beukes, D. M. Bower, R. M. Hazen, and D. J. Swift. 2008. "An actualistic perspective into Archean worlds – (cyano-)bacterially induced sedimentary structures in the siliciclastic Nhlazatse Section, 2.9 Ga Pongola Supergroup, South Africa." Geobiology, 6: 5-20 [10.1111/j.1472-4669.2007.00118.x]

    Non-Refereed

    Curran, N., D. Bower, and B. Cohen. 2017. "Near-Surface Age Distribution of Lunar Impact-Melt Rocks." 2017 Annual Meeting of the Lunar Exploration Analysis Group 2041:

    Bower, D., N. Curran, and B. Cohen. 2017. "Determining the Mineralogy of Lunar Samples Using Micro Raman Spectroscopy: Comparisons Between Polished and Unpolished Samples." 2017 Annual Meeting of the Lunar Exploration Analysis Group 2041:

    Lewis, J. M., J. L. Eigenbrode, A. C. Mcadam, et al. S. Andrejkovicova, C. Knudson, G. Wong, M. Millan, C. Freissinet, C. Szopa, X. Li, and D. M. Bower. 2017. "The Preservation and Detection of Organic Matter within Jarosite." AGU Fall Meeting [Full Text (Link)]

    Positions/Employment

    1/2009 - 1/2012

    NAI Postdoctoral Program Fellow

    Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC

    Experimental and observational approaches to using minerals as biosignatures in ancient
    rocks: perfecting analytical techniques to identify life on early Earth and on other planets
     

    1/2012 - 6/2012

    Adjunct Professor

    Tidewater Community College, Norfolk, VA

    Oceanography, Natural Sciences Department

    Education

    PhD Ocean, Earth, and Atmospheric Science 2003-2008
    Old Dominion University, Norfolk, Virginia
    Dissertation: Microtextures of cyanobacterial mats in siliciclastic sedimentary environments (modern & ancient): applications to the search for life on Mars

    B.Sc. Oceanography / B.A. Geology 1998-2003
    Richard Stockton College of New Jersey, Pomona, New Jersey
     

    Talks, Presentations and Posters

    Invited

    Detecting Microbial Life with Raman Spectroscopy: Applications to Ocean Ecology

    12 / 5 / 2019

    Raman spectroscopy is a non-destructive vibrational spectroscopy technique that provides real-time characterization of the chemical and physical structure of materials for Earth and planetary science, forensics, the medical and dental field, archaeology, and oceanographic research. Raman data include spectra that record specific molecular configurations and spectral maps that provide insights to spatial relationships and small-scale variations that are not easily distinguished using other methods. Terrestrial microbial ecosystems are typically intertwined with geochemical processes. In the ancient rock record, geochemical signatures such as biominerals or chemical gradients are often the main indicator of a relict biome, and spatial relationships are crucial to reconstructing the original ecosystem. In many modern sedimentary environments, microbial populations and geochemical processes are constantly changing on short time scales. Fast, compound-specific techniques like Raman spectroscopy are necessary to characterize the nature and diversity of these dynamic environments. For oceanographic research, Raman spectroscopy is used to determine salinity, temperature, gas composition, organic matter composition, and pigment distribution in the ocean or glacial ice. Raman spectroscopy can be deployed for in situ or measurements, as well as for remote sensing. The portability and utility of Raman systems make the technique a valuable asset for field research, providing an “all in one” method for determining multiple seawater characteristics for both deep sea and surface ocean measurements.
     

    Searching for fossilized life on other planets: Insights from the geochemical characterization of terrestrial sedimentary rocks

    9 / 21 / 2019

    Different types of ancient terrestrial sedimentary deposits contain compelling microtextures and chemical components that may be biosignatures indicative of early life on Earth. These biosignatures are useful for the search for life on other planets, like Mars, with similar lithologies. Unfortunately on Earth, multiple processes over geologic time result in the alteration of the rocks which can obscure otherwise syngenetic biosignatures and likewise create false signatures in the form of secondary carbon emplacement or mineral phase changes making it difficult to accurately ascertain their origins. Here I will present some of the ways in which I try to understand the differences between true biosignatures and abiotic signatures using experimental and observational methods. This includes some discussion on the experimental simulation of cyanobacterial biomineralization and fossilization in sandy sediments with a larger focus on the characterization of fossil bio-relevant features and their host materials in ancient sedimentary rocks using micro Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron probe microanalysis (EPM). Upcoming Mars astrobiology missions will focus on siliceous lithologies similar to hydrothermal deposits on Earth. Some of these possible mars analogs include the ~400 Ma Rhynie chert (Scotland), 1.88 Ga Gunflint Formation (Ontario, Canada), and three chert units from the Pilbara (Australia), the ~3.42 Ga Strelley Pool Formation, ~3.46 Ga Apex basalt, and ~3.49 Ga Dresser Formation. The collective results show that at least two main factors may hinder direct comparisons between the younger, unambiguously biotic chert samples with the older chert ambiguous samples: 1) the macromolecular carbon (MMC) in the younger cherts was originally more complex with a diversity of multicellular and unicellular organisms, whereas the MMC in the older cherts had much simpler structural origins, 2) the degree of geologic processing experienced by the older cherts resulted in alteration and recrystallization of the host quartz, MMC, and associated mineral assemblages, which is not seen in the younger cherts. Despite these factors, the possibility remains that we can establish biosignatures that are specific to each individual hydrothermally-influenced paleoenvironment and ultimately use these signatures in upcoming life detection missions.

    Ocean, Earth, and Atmospheric Science Department Seminar, Old Dominion University, Norfolk, VA

    The Variability of Biosignatures Through Geologic Time

    9 / 12 / 2017

    The identification of biosignatures in ancient rocks is hampered by the effects of geologic time. Micro Raman spectroscopy can be used to characterize morpholgical and chemical features in terrestrial cherts. Some of the oldest cherts are useful as analogs for siliceous lithologies on Mars. The older the cherts on Earth, however, the more ambiguous the signatures indicative of life become. The implications of these difficulties and the recent advances in understaning are discussed with an emphasis on applications to upcoming Mars rover missions.

    EON Workshop, Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan

    The geochemical characterization of ancient terrestrial rocks using micro Raman spectroscopy: applications to the search for life beyond Earth

    9 / 26 / 2017

    Ancient terrestrial rocks contain some of the most compelling microtextures and geochemical signatures indicative of early life on Earth. Some of these rocks are good analogs for other planetary environments where similar deposits have been identified. Unfortunately the geologic events that occurred over billions of years on Earth have obscured otherwise syngenetic biosignatures and likewise created false signatures in the form of secondary carbon emplacement or diagenetic phase changes. Typically the younger rocks ≤ 2 Ga, contain unambiguous evidence for life, but the origins of fossil features in much older rocks are more difficult to clearly ascertain. Here confocal micro Raman spectroscopy and imaging are used to characterize the chemical composition and spatial relationships of mineral phases and carbonaceous materials in ancient fossil-bearing chert deposits from the ~400 Ma Rhynie, 1.88 Ga Gunflint, ~3.42 Ga Strelley Pool, ~3.46 Ga Apex, and ~3.49 Ga Dresser Formations. Our results show some similarities between the younger and older samples, but the mineral and carbon signatures in the older samples are more indicative of abiotic processes. The exploration of these types of deposits with Raman spectroscopy is of particular relevance to upcoming life detection missions on Mars, and the unambiguous detection of biosignatures in these rocks will be important for the success of these missions.

    WITec 14th Confocal Raman Imaging Symposium, Ulm, Germany

    From MARS Major to Mars Scientist: My Journey from the Ocean to Space

    10 / 21 / 2016

    Biology Seminar, Stockton University, Pomon, NJ

    Applications of Micro Raman Spectroscopy: Microfossils and Astrobiology

    4 / 5 / 2016

    Micro Raman imaging is essential in the study of microfossils in the context of astrobiology, because the technique is non-destructive, spectral signatures are useful in identifying compounds that are relevant to biologic processes, and the imaging capabilities establish spatial relationships and make it easy to put the identified features in context.

     

    WITec Micro Raman Imaging Workshop, Rutgers University, Newark, NJ  April 5-6, 2016

    Understanding the origins of possible cyanobacterial biosignatures in ancient siliciclastic rocks

     

    Geological Society of Washington

    9 / 30 / 2015

    Cyanobacteria are well-known architects of modern microbial mats and likely thrived on Earth as far back as the Archean. Siliciclastic sediments in particular are home to a wide variety of microbial mat communities, yet traces of their ancestors in ancient siliciclastic rocks are difficult to detect.The results suggest that over time, the collection of morphological, mineralogical, and carbonaceous features that formed at the end of incubation experiments could ultimately create the laminations characteristic of microbial mats found in ancient sandstones.

    Incubation studies of cyanobacteria and natural ilmenites (FeTiO3): understanding the co-evolution of microbes and minerals during diagenesis

     

    Geochemistry Seminar Series, Geology Department, University of Maryland, College Park

    9 / 2011

    The contribution of benthic mat-building cyanobacteria to weathering and compositional changes to minerals in sandy sediments is not typically considered. To understand the influence of cyanobacterial mats on mineral weathering, incubation exepriments using abiotic controls for comparison were done using ilmenite sands and ilmenite enriched beach sands over 5 months at 3 temperature steps. A large variety of mineral phases formed only in the samples incubated with cyanobacteria, suggesting that cyanobacteria do indeed play an important role in sediment weathering.

    Investigations of the nature and provenance of mineral and carbonaceous material in fossiliferous cherts: revisiting the 1.9 Ga Gunflint Formation

     

    Geological Society of Washington

    2 / 17 / 2010

    The Gunflint cherts represent an ancient microbial ecosystem as evidenced by the ample microfossils and carbon signatures. Using micro Raman spectroscopy, the composition and spatial relationships of microfossils and other features can be readily attained. In the Gunflint samples, carbon is not limited to the microfossils, but is also found within the quartz grain interstices. The results suggest a post-depositional emplacement of some of the carbon in theses samples, possibly by hydrothermal overprint.

    Other

    In Situ Raman and Reflectance Spectroscopy for Planetary Science

    11 / 22 / 2019

    Wide Field Time-Resolved Raman Spectrometer for Planetary Science

    11 / 7 / 2019

    Planetary and small body missions continue to seek instrumentation that comprehensively characterize the composition of the planetary surface and/or near-subsurface materials. raman spectroscopy is uniquely suited for planetary exploration because of its ability to identify minerals, organic compounds, and biomarkers with both in situ and at distance (1-100m) measurements. We developed a compact spatial heterodyne spectrometer (SHS) with high efficiency YB:YAG fiber lasers for time-resolved, high-resolution dual-wavelength (VIS-NIR) Raman spectroscopy.

    Correlated Raman and Reflectance Spectroscopy for in situ Lunar Resource Exploration

    7 / 16 / 2019

    A composite instrument combining Raman spectros-copy and reflectance spectroscopy will enable rapid, nondestructive, passive characterization of planetary surface materials to identify trace compounds without sample preparation. The Rapid Optical Characteriza-tion Suite for in situ Target Analysis of Lunar Rocks (ROCSTAR) is designed to search for minerals and volatiles in lunar materials using a combined package of time-resolved visible (VIS) 532 nm and near-infrared (NIR) 785 nm Raman, supported by near-Infrared/mid-Infrared (NIR-MIR) reflectance spectros-copy. ROCSTAR implements mature vibrational spectroscopy techniques to probe for chemical species of significance in lunar prospecting. Resource identifica-tion is critical to develop a viable long-term lunar ex-ploration program enabling a continued human presence. ROCSTAR capabilities will enable rapid quanti-tative measurements on lunar surface materials while reducing the need for mechanical or thermal processing to evaluate water and metal contents. Water is a priority resource essential to life support, facility opera-tions, and synthesizing fuels. Mineral-bound metals are important resource targets in regolith and mare basalts [1]. Lunar minerals ilmenite and pyroxene are known hosts of metals like Cr, Ni, Co, and Mn, and ilmenite in particular has been considered for Fe and O2 extraction [2][3].
    Raman spectroscopy provides structural infor-mation to identify trace compounds, including minerals, in a matter of seconds. Raman spectroscopy has been used for decades to measure the composition of returned lunar samples and analog materials ([4][5][6] and references therein). Reflectance spectroscopy has a strong lunar mission heritage to build on, having been used for decades to evaluate the mineralogy of the lunar surface via remote measurements from orbital plat-forms like Galileo, Clementine, Lunar Prospector, and the Moon Mineralogy Mapper (M3) on Chandrayaan 1, as well as multiple Earth-based telescope measure-ments [7][8][9] The two complimentary techniques, used together, ensure near-comprehensive identification and accurate characterization of lunar materials suitable for resource extraction. Our main goal is to provide the means for in situ standalone identification of priority resource materials on the lunar surface with minimal power needs in an compact package. The architecture of ROCSTAR ensures adaptability to any mission platform, whether that be inside a lander/rover or extended on a robotic arm, or as a handheld device carried by astronauts. ROCSTAR can determine the composition, variety, and distribution of minerals, metals, and water with correlated spectroscopic meas-urements. These measurements are achieved by point-ing ROCSTAR’s probe at a target at a distance of a few mm with sequential activation of MIR-NIR reflec-tance acquisitions followed by NIR-VIS Raman acqui-sitions, each for ~0.5 – 40s integration time (depending on the target material).

    Detecting Biosignatures in Ocean Worlds Brines with Raman and Reflectance Spectroscopy

    6 / 26 / 2019

    Ocean Worlds (OW) like Europa and Enceladus are covered in icy shells that surround a watery interior. Remote observations indicate that plumes and cracks are possible vehicles for the deposition of subsurface materials like salts and organics. Exposure to the harsh environmental conditions on the surfaces of these moons, however, creates an additional barrier to the interpretation of surface sample measurements; e.g., ionizing irradiation causes the breaking of molecular bonds and disintegration of macro-molecules resulting in a completely different molecular structure from what was originally present beneath the icy surface (Ferrini et al., 2004). Pristine subsurface material deposited near a vent or plume will likely evolve in time by cosmic ray gardening and vacuum exposure. Thus, an understanding of the change in spectroscopic properties of representative compounds as a function of weathering is important.
    UV/Vis/IR spectrometers (Galileo/NIMS, Cassini/VIMS+CIRS) have a long heritage of remote measurements of OW such as Titan, Enceladus, and Europa providing information on the rich chemical inventory of these bodies. However, the km-scale footprints and spectral sensitivity of these spectrometers miss trace species, including possible macromolecules, dispersed on the surface. Robotic in-situ Raman spectroscopy is a versatile and non-destructive tool that is well-established for in situ measurements for the detection of minerals and a wide variety of compounds in host materials like rocks and ice.
    The optical properties of water are modified by salts and other impurities resulting in frequency shifts in Raman spectral signatures. For example, salts like NaCl or KCl are either inactive or very weak Raman scatterers, but their presence is revealed in frequency shifts particularly in the water bands ~3200 and ~3400 cm-1 (Wu et al., 2016). Conversely, Raman spectral signatures for sulfosalts and organics are easily resolved along with the host ice (Fig.1). Reflectance spectroscopy provides a way to verify Raman measurements (and visa-versa) using IR fundamental, overtone, and combination vibrational transitions. Data collected using laboratory IR spectrometers and Galileo/NIMS show that chloride salts have distinct peak characteristics (Hanley et al., 2013). With the two techniques combined, a complete characterization of materials in ice can be accomplished. Here we present our initial findings from laboratory experiments using portable and bench top Raman and reflectance spectroscopy along with fluorescence microscopy to characterize salt- and organics-infused water ices. We will also discuss the integration of irradiation experiments to discern the effects of surface exposure on Raman and reflectance spectra of salts and organic materials in icy substrates.

    INDICATORS OF SUBSURFACE COMPOSITION ON OCEAN WORLDS DETECTED BY RAMAN AND REFLECTANCE SPECTROSCOPY

    5 / 21 / 2019

    Ocean Worlds (OW) like Europa and Enceladus are covered in icy shells that obscure much of the process-es and chemical composition within the moons’ watery interior. Remote observations indicate that plumes and cracks are possible vehicles for subsurface materials like salts and organics to reach the icy surface. These surface materials may provide clues to the subsurface chemical environment. Exposure to the harsh radiation environment on the surfaces of these moons, however, creates an additional barrier to the interpretation of surface sample measurements.. Ionizing irradiation causes the breaking of molecular bonds and disintegra-tion of macro-molecules resulting in a completely dif-ferent molecular structure from what was originally present [1]. Pristine subsurface material deposited near a vent or plume will likely evolve in time by cosmic ray gardening. Thus, an understanding of the change in spectroscopic properties of representative compounds as a function of weathering is important..
    UV/Vis/IR spectrometers (Galileo/NIMS, Cassi-ni/VIMS+CIRS) have a long heritage of remote meas-urements of OW such as Titan, Enceladus, and Europa providing information on the rich chemical inventory of these bodies. However, the km-scale footprints and spectral sensitivity of these spectrometers miss trace species, including possible macromolecules, dispersed on the surface. Robotic in-situ Raman spectroscopy is a versatile and non-destructive tool that is well-established for in situ measurements for the detection of minerals and a wide variety of compounds in host materials like rocks and ice. A Composite Vibrational Spectrometer (CVS) consisting of co-registered Ra-man, fluorescence and reflectance spectrometers will provide valuable information on indicators of subsur-face composition, when used in concert with other in-situ analytical techniques. In conjunction with space-craft remote spectrometers, an in situ CVS will aid characterization of surface materials on different spatial scales providing context for transport processes. The optical properties of water are modified by salts and other impurities resulting in frequency shifts in Raman spectral signatures. For example, salts like NaCl or KCl are either inactive or very weak Raman scatterers, but their identity is revealed in shifts partic-ularly in the water bands ~3200 and ~3400 cm-1 [2] (Wu et al., 2016). Conversely, Raman spectral signatures for sulfosalts and organics are easily resolved along with the host ice (Fig.1). Reflectance spectroscopy provides a way to verify Raman measurements (and visa-versa) using IR fundamental, overtone, and com-bination vibrational transitions. Data collected using laboratory IR spectrometers and NIMS show that chlo-ride salts have distinct peak characteristics [3] (Hanley et al., 2013). With the two techniques combined, a complete characterization of materials in ice can be accomplished.

    Understanding Life Signatures Across Geothermal-Ice Gradients in Europa-like environments using Raman spectroscopy

    10 / 10 / 2018

    Ocean worlds like Europa exhibit geophysical and geochemical characteristics that are similar to terrestrial icy environments. The interface of geothermal activity with icy terrestrial environments is a dynamic setting where microbes thrive and the composition of surface sediments is ephemeral. Icy materials that interface with geothermal activity can entrain microbes, rocks and minerals, as well as gases, and in the absence of readily identifiable biosignatures, geochemical gradients derived from biological processes can offer clues to the presence of life. Some of these geochemical gradients are distinguished by subtle variations in mineral assemblages. Deviations in mineral structure can be attributed to the incorporation of cations used in metabolic processes or from the influence of decaying organic matter on local chemistry. Raman spectroscopy is a powerful, versatile, and non-destructive tool that is well-established for in situ measurements and the detection of minerals and compounds in a wide variety of host materials like rocks and ice. To test the utility of Raman spectroscopy for supporting life detection investigations on Europa-like materials, Raman measurements were made on laboratory-synthesized Europa analogs along with rocks and ice collected near the Kverkfjöll volcano-Vatnajokull glacier in Iceland. Here we present our initial findings and discuss future directions in developing Raman spectroscopy instrumentation for life detection on Europa-like worlds.

    Teaching Experience

    Adjunct Instructor:

    Tidewater Community College, Norfolk, VA (2012) Introduction to Oceanography

    Old Dominion University, Norfolk, VA (2008) Introduction to Oceanography, Physical Geology

     

    Teaching Assistant:

    Old Dominion University, Norfolk, VA (2007) Paleontology

    Richard Stockton University, Pomona, NJ (2001-2003) Physical Geology, Chemical Oceanography

    Professional Societies

    Geochemical Society, 2010 - Present
    Geological Society of America, 2000 - Present
    American Geophysical Union, 1999 - Present

    Grants

    05/01/2018 - 05/31/2020 ISFM/FLaRe, NASA, NASA NRA #: ISFM

    Exploring radiolytic production of chlorinated and sulfurized organic molecules on Mars and Europa

    ; Co-I, Raman spectroscopy lead ; 0.25 FTE
    01/01/2019 - 01/01/2020 ISFM/FLaRe, NASA, NASA NRA #: ISFM

    Biogeochemical characterization of returned samples from a potential ocean worlds analog site using Raman and reflectance spectroscopy

    ; PI and Science lead ; 0.2 FTE
    01/01/2019 - 01/01/2020 IRAD, NASA, NASA NRA #: IRAD

    Wide field, time-resolved Raman spectrometer for planetary science

    ; Co-I, science lead ; 0.1 FTE
    04/01/2019 - 04/01/2020 ISFM/FLaRe, NASA, NASA NRA #: ISFM

    Habitability of basaltic subsurface environments

    ; Co-I, Raman lead ; 0.1 FTE

    Awards

    NASA Astrobiology Institute Postdoctoral Fellowship 2009-2012
    National Prominence Award, Old Dominion University, Norfolk, Virginia 2003-2004
    NSF Research Experience for Undergraduates, Shannon Point Marine Center, WA 2002
    Distinguished Student Fellowship Award, Richard Stockton College of New Jersey
     

    Selected Public Outreach

    Chair, Gordon Research Seminar on Geobiology 1 / 2013 - 1 / 2013
    https://www.grc.org/programs.aspx?id=15607

    The Future of Geobiology: Perspectives from Graduate and Postdoctoral Research

    The focus of this meeting is to explore the diverse and dynamic field of geobiology . The discussions and presentations will address these main themes:

    • microbial structures in ancient and modern settings
    • taphonomy and micropaleontology
    • biomineralization and the co-evolution of minerals and microbes
    • life detection for applications to early life on Earth and other planets
    • integrating geobiobiology into interdisciplinary research and academic programs

    Special Experience

    Dr. Bower has many years of field experience in a wide variety of environments:

    Recent (2016-2019):

    Yellowstone National Park (2019): In situ Raman measurements and sample collection of silicified microbial mats in snow-covered hot springs.

    Vatnajokul Glacier, Iceland (2018): In situ Raman measurements and sample collection of volcanic rocks, sediments, and ice.

    Dinosaur Provincial Park, Alberta, Canada (2016): sample collection and scouting for future instrument testing

    Fieldwork Pre-2015:

    Pongola Supergroup, South Africa (2005) : mapping, sketching, videography, and sample collection of sandstones. 

    Fisherman's Island, Virginia (2005-2007): transects of tidal flats, collection of microbial mat samples.

    Biosignatures in Ancient Rocks Workshop, Ontario, Canada (2007): collection of Gunflint cherts and samples from rock successions related to the Sudbury impact event

    Gros Morne National Park, Newfoundland, Canada (2009,2010): "clean" field methods to asses life in serpentinzed ophiolite sequence; CHEMin portable XRD field analysis of carbonates.

    White Sands, New Mexico (2009): collection of microbial mats and sulfates in gypsum dunes; Delta Nu portable Raman (785 nm) field analysis of sulfates.

    Saskatchewan, Canada (2009): sample collection of halophilic microbial mats.

    Mono Lake, California (2010): videographer for rover drill prototype

    Brief Bio

    Dr. Dina Bower is an interdisciplinary scientist with a background in marine chemistry and mineralogy. She has focused much of her career on geochemistry and life detection in the context of reconstructing early life on Earth. Dr. Bower has several years of experience utilizing Raman spectroscopy and spectroscopic imaging for in situ field measurements and high-resolution laboratory applications. Her expertise is complemented with the use of other analytic approaches to characterize a wide variety of bio-geologic materials, including microscopy-optical petrography, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), electron probe microanalysis, cathodoluminescence, and reflectance spectroscopy. Dr. Bower applies her knowledge of biogeochemical science requirements and hands on expedition experience to the development of spectroscopic instruments and hybridized systems for field work and planetary missions.

    Publications

    Refereed

    Chan, M. A., N. W. Hinman, S. L. Potter-McIntyre, et al. K. E. Schubert, R. J. Gillams, S. M. Awramik, P. J. Boston, D. M. Bower, D. J. Des Marais, J. D. Farmer, T. Z. Jia, P. L. King, R. M. Hazen, R. J. Leveille, D. Papineau, K. R. Rempfert, M. Sanchez-Roman, J. R. Spear, G. Southam, J. C. Stern, and H. J. Cleaves. 2019. "Deciphering Biosignatures in Planetary Contexts." Astrobiology 19 (9): 1075-1102 [10.1089/ast.2018.1903]

    Callefo, F., F. Ricardi-Branco, G. Hartmann, et al. D. Galante, F. Rodrigues, L. Maldanis, E. Yokoyama, V. Teixeira, N. Noffke, D. Bower, E. Bullock, A. Braga, J. Coaquira, and M. Fernandes. 2019. "Evaluating iron as a biomarker of rhythmites — An example from the last Paleozoic ice age of Gondwana." Sedimentary Geology 383 1-15 [10.1016/j.sedgeo.2019.02.002]

    Bower, D. M., D. R. Hummer, and A. Steele. 2017. "AN EXPERIMENTAL LOOK AT THE TAPHONOMY OF CYANOBACTERIAL MATS IN SILICICLASTIC SEDIMENTS." PALAIOS 32 (12): 725-738 [10.2110/palo.2017.016]

    Bower, D. M., A. Steele, M. D. Fries, O. R. Green, and J. F. Lindsay. 2016. " Raman imaging spectroscopy of a putative microfossil from the ~3.46 Ga Apex Chert: insights from quartz crystal orientation ." Astrobiology 16 (2): [10.1089/ast.2014.1207]

    Bower, D. M., D. R. Hummer, A. Kyono, and A. Steele. 2015. "The co-evolution of Fe-,Ti-oxides and other microbially induced mineral precipitates in sandy sediments: understanding the role of cyanobacteria in weathering and early diagenesis ." Journal of Sedimentary Research 85 1213-1227 [10.2110/jsr.2015.76]

    Bower, D. M., A. Steele, M. D. Fries, and L. Kater. 2013. "Micro Raman spectroscopic investigations of carbonaceous material in microfossils and meteorites: improving the use of G- and D-band parameters for life detection." Astrobiology 13 (1): 103-113 [10.1089/ast.2012.0865]

    Szponar, N., W. J. Brazelton, M. O. Schrenk, et al. D. M. Bower, A. Steele, and P. L. Morrill. 2013. "Geochemistry of a continental site of serpentinization in the Tablelands Ophiolite, Gros Morne National Park: a Mars analogue ." Icarus 224 286-296 [10.1016/j.icarus.2012.07.004]

    Bower, D. M. 2011. "Micro Raman spectroscopic investigations of laminae associated mineral assemblages in 2.9 Ga sandstones of the Pongola Supergroup, South Africa." Journal of Raman Spectroscopy 42 (8): 1626-1633 [10.1002/jrs.2903]

    Noffke, N., N. Beukes, D. M. Bower, R. M. Hazen, and D. J. Swift. 2008. "An actualistic perspective into Archean worlds – (cyano-)bacterially induced sedimentary structures in the siliciclastic Nhlazatse Section, 2.9 Ga Pongola Supergroup, South Africa." Geobiology 6 5-20 [10.1111/j.1472-4669.2007.00118.x]

    Non-Refereed

    Curran, N., D. Bower, and B. Cohen. 2017. "Near-Surface Age Distribution of Lunar Impact-Melt Rocks." 2017 Annual Meeting of the Lunar Exploration Analysis Group 2041

    Bower, D., N. Curran, and B. Cohen. 2017. "Determining the Mineralogy of Lunar Samples Using Micro Raman Spectroscopy: Comparisons Between Polished and Unpolished Samples." 2017 Annual Meeting of the Lunar Exploration Analysis Group 2041

    Lewis, J. M., J. L. Eigenbrode, A. C. Mcadam, et al. S. Andrejkovicova, C. Knudson, G. Wong, M. Millan, C. Freissinet, C. Szopa, X. Li, and D. M. Bower. 2017. "The Preservation and Detection of Organic Matter within Jarosite." AGU Fall Meeting [Full Text (Link)]

                                                                                                                                                                                            
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