Hematite Spherules on Mars

In 2004, the observation of large amounts of hematite spherules on Mars by the NASA’s Mars Exploration Rover “Opportunity,” which landed in Eagle crater on Meridiani Planum, created tremendous excitement among the scientific community. The discovery of hematite was significant as it suggests past presence of water on Mars. Furthermore, the hematite spherules were widely suggested to be concretions that formed by precipitation of aqueous fluids. Among the various observed mysteries of Martian hematite spherules, also known as “blueberries,” one regarding to their size limit was very puzzling. All of the millions of blueberries observed on Mars were smaller than 6.2 mm in diameter. Because the concretions on Earth are not limited in size, the formation of the Martian blueberries became difficult to explain. In this chapter, we will discuss the observed properties of Martian hematite spherules and explain why a cosmic spherule formation mechanism provides a possible solution to the puzzling observations on Mars

Biosignature detection by Mars rover equivalent instruments in samples from the CanMars Mars Sample Return Analogue Deployment

The University of Winnipeg's HOSERLab was established with funding from the Canada Foundation for Innovation, the Manitoba Research Innovations Fund and the Canadian Space Agency, whose support is gratefully acknowledged. This study was supported with grants from the Canadian Space Agency through their FAST program, NSERC, and UWinnipeg.This work details the laboratory analysis of a suite of 10 samples collected from an inverted fluvial channel near Hanksville, Utah, USA as a part of the CanMars Mars Sample Return Analogue Deployment (MSRAD). The samples were acquired along the rover traverse for detailed off-site analysis to evaluate the TOC and astrobiological significance of the samples selected based on site observations, and to address one of the science goals of the CanMars mission: to evaluate the ability of different analytical techniques being employed by the Mars2020 mission to detect and characterize any present biosignatures. Analytical techniques analogous to those on the ExoMars, MSL and the MER rovers were also applied to the samples. The total organic carbon content of the samples was <0.02% for all but 4 samples, and organic biosignatures were detected in multiple samples by UV–Vis–NIR reflectance spectroscopy and Raman spectroscopy (532 nm, time-resolved, and UV), which was the most effective of the techniques. The total carbon content of the samples is < 0.3 wt% for all but one calcite rich sample, and organic C was not detectable by FTIR. Carotene and chlorophyll were detected in two samples which also contained gypsum and mineral phases of astrobiological importance for paleoenvironment/habitability and biomarker preservation (clays, gypsum, calcite) were detected and characterized by multiple techniques, of which passive reflectance was most effective. The sample selected in the field (S2) as having the highest potential for TOC did not have the highest TOC values, however, when considering the sample mineralogy in conjunction with the detection of organic carbon, it is the most astrobiologically relevant. These results highlight importance of applying multiple techniques for sample characterization and provide insights into their strengths and limitations.PostprintPeer reviewe

Raman Spectroscopy for Planetary Exploration and Characterization of Extraterrestrial Materials

Ph.D. University of Hawaii at Manoa 2016.Includes bibliographical references.The sharp spectral features of Raman spectra are widely recognized to provide unequivocal and accurate chemical characterization of organic and inorganic compounds. Therefore Raman spectroscopy can be used to detect minerals, water bearing minerals, organic and biological materials and biomarkers in the context of planetary science. This dissertation extends the applicability of the Raman technique both laboratory based micro-Raman and remote Raman sensing ahead of planetary exploration missions to Mars employing Raman spectrometers. The interpretation of Raman imaging from a meteorite taken with a micro-Raman system revealed a close correlation between the blue color in natural ringwoodite and a new observed Raman peak that shows strong resonance Raman enhancement. The data suggest that ringwoodite exists both in the spinel structure and in the partially inverse spinel structure. In the field of remote Raman, this dissertation provides carefully derived Raman cross-section values for various organic liquids and inorganic polyatomic ions in aqueous solutions that will be useful for estimating detection capabilities of 532 nm excitation remote Raman systems for planetary exploration. Suitability of remote 532 nm Raman systems for future applications is explored. A portable, compact time-resolved instrument using a 3-inch diameter telescope is used it to demonstrate daytime detection of amino acids and nucleobases from a distance of 8 m. The measurements with a larger 8-inch Raman system demonstrate that it is possible to acquire good quality Raman spectra of various materials from a 430 meter remote distance during daylight with detection times of 10 seconds, and in some cases as short as 1 second, during daylight and in a realistic outdoor context. To my knowledge, these are the only remote Raman spectra at this distance that provide unambiguous detection of compounds important for planetary science, such as water and water ice, dry ice, sulfur, sulfates, various minerals and organics, and atmospheric gases. This dissertation demonstrates the large potential of micro-Raman investigations and the significant improvement of the remote Raman technique as well as its suitability for Solar System exploration

Enhancement of the Anti-Stokes Fluorescence of Hollow Spherical Carbon Nitride Nanostructures by High Intensity Green Laser

Fluorescence spectra of graphitic (g-C3N4) and spherical (s-C3N4) modifications of carbon nitride were measured as a function of green pulsed (6 ns-pulse) laser intensity. It was found that the intensity of the laser increases the maximum of the fluorescence shifts towards the anti-Stokes side of the fluorescence for s-C3N4 spherical nanoparticles. This phenomenon was not observed for g-C3N4 particles. The maximum of the anti-Stokes fluorescence in s-C3N4 nanoparticles was observed at 480 nm. The ratio of the intensity of the anti-Stokes peak (centered at 480 nm) to that of the Stokes peak (centered at 582 nm) was measured to be I484/582 = 6.4 × 10−3 at a low level of intensity (5 mW) of a green pulsed laser, whereas it rose to I484/582 = 2.27 with a high level of laser intensity (1500 mW)

Biosignature detection by Mars rover equivalent instruments in samples from the CanMars Mars Sample Return Analogue Deployment

This work details the laboratory analysis of a suite of 10 samples collected from an inverted fluvial channel near Hanksville, Utah, USA as a part of the CanMars Mars Sample Return Analogue Deployment (MSRAD). The samples were acquired along the rover traverse for detailed off-site analysis to evaluate the TOC and astrobiological significance of the samples selected based on site observations, and to address one of the science goals of the CanMars mission: to evaluate the ability of different analytical techniques being employed by the Mars2020 mission to detect and characterize any present biosignatures. Analytical techniques analogous to those on the ExoMars, MSL and the MER rovers were also applied to the samples. The total organic carbon content of the samples was &lt;0.02% for all but 4 samples, and organic biosignatures were detected in multiple samples by UV–Vis–NIR reflectance spectroscopy and Raman spectroscopy (532 nm, time-resolved, and UV), which was the most effective of the techniques. The total carbon content of the samples is &lt; 0.3 wt% for all but one calcite rich sample, and organic C was not detectable by FTIR. Carotene and chlorophyll were detected in two samples which also contained gypsum and mineral phases of astrobiological importance for paleoenvironment/habitability and biomarker preservation (clays, gypsum, calcite) were detected and characterized by multiple techniques, of which passive reflectance was most effective. The sample selected in the field (S2) as having the highest potential for TOC did not have the highest TOC values, however, when considering the sample mineralogy in conjunction with the detection of organic carbon, it is the most astrobiologically relevant. These results highlight importance of applying multiple techniques for sample characterization and provide insights into their strengths and limitations

Cryogenic Minerals in Hawaiian Lava Tubes: A Geochemical and Microbiological Exploration

The Mauna Loa volcano, on the Island of Hawaii, has numerous young lava tubes. Among them, two at high altitudes are known to contain ice year-round: Mauna Loa Icecave (MLIC) and the Arsia Cave. These unusual caves harbor cold, humid, dark, and biologically restricted environments. Secondary minerals and ice were sampled from both caves to explore their geochemical and microbiological characteristics. The minerals sampled from the deep parts of the caves, where near freezing temperatures prevail, are all multi-phase and consist mainly of secondary amorphous silica SiO2, cryptocrystalline calcite CaCO3, and gypsum CaSO4·2H2O. Based on carbon and oxygen stable isotope ratios, all sampled calcite is cryogenic. The isotopic composition of falls on the global meteoric line, indicating that little evaporation has occurred. The microbial diversity of a silica and calcite deposit in the MLIC and from ice pond water in the Arsia Cave was explored by analysis of ∼50,000 small subunit ribosomal RNA gene fragments via amplicon sequencing. Analyses reveal that the Hawaiian ice caves harbor unique microbial diversity distinct from other environments, including cave environments, in Hawaii and worldwide. Actinobacteria and Proteobacteria were the most abundant microbial phyla detected, which is largely consistent with studies of other oligotrophic cave environments. The cold, isolated, oligotrophic basaltic lava cave environment in Hawaii provides a unique opportunity to understand microbial biogeography not only on Earth but also on other planets

Jezero Crater Floor and Delta Chemistry and Mineralogy Observed by SuperCam in the First 1.5 Years of the Perseverance Rover Mission

International audienceJezero crater was chosen for exploration and sample collection by Perseverance due to its history as a lake with river deltas, its diverse mineralogy, including carbonates observed from orbit, and as a potential site to calibrate crater counting ages with radiometric dates of samples to be returned to Earth. This presentation focuses on the results of SuperCam, which uses LIBS for remote elemental chemistry, VISIR and remote Raman spectroscopy for mineral compositions and alteration, includes a microphone, and performs high-resolution imaging for textures and morphology. In the first year after landing, SuperCam and other instruments were used to explore Jezero’s floor. We found that all of the floor units are igneous, with lava flows comprising the upper units as part of the Máaz formation, while the lower formation, Séítah, is an olivine cumulate, produced by gravitational settling of olivine crystals in a large melt body. Artuby ridge, just outside the SW portion of Séítah and stratigraphically just above it, contains up to 60% pyroxene. The upper portions of the Máaz formation are more enriched in plagioclase, with the uppermost Ch’al member having the most evolved composition, along with the Content member, pitted rocks directly overlying the main cumulate portion of Séítah. After exploring the floor, Perseverance drove to the delta formation and began a walk-about style of observations starting at Enchanted Lake, just below an arm of the delta formation, and then moving into Hawksbill Gap, climbing 18 m in elevation between Devil’s Tanyard, Sunset Hill, and Hogwallow flats. Delta compositions initially displayed higher phyllosilicate contents, identified by absorptions at 1.4, 1.9, and 2.3 µm, and by higher LIBS H peak areas. Farther up, compositions changed to sulfur-bearing in lower locations within the continuous fine-grained light-toned strata (e.g., Pignut Mountain, Sol 463) and carbonate-rich in upper strata. Veins were observed, consisting of Mg-Fe carbonate (Elder Ridge, Sol 459) and anhydrite (Reid’s Gap, Sol 466). The sulfates suggest precipitation of these salts at a later stage, as the lake was evaporating. Carbonates and sulfates in veins in different locations indicate that groundwater was active in the lithified sediments and had significantly different chemistry at different intervals

Jezero Crater Floor and Delta Chemistry and Mineralogy Observed by SuperCam in the First 1.5 Years of the Perseverance Rover Mission

International audienceJezero crater was chosen for exploration and sample collection by Perseverance due to its history as a lake with river deltas, its diverse mineralogy, including carbonates observed from orbit, and as a potential site to calibrate crater counting ages with radiometric dates of samples to be returned to Earth. This presentation focuses on the results of SuperCam, which uses LIBS for remote elemental chemistry, VISIR and remote Raman spectroscopy for mineral compositions and alteration, includes a microphone, and performs high-resolution imaging for textures and morphology. In the first year after landing, SuperCam and other instruments were used to explore Jezero’s floor. We found that all of the floor units are igneous, with lava flows comprising the upper units as part of the Máaz formation, while the lower formation, Séítah, is an olivine cumulate, produced by gravitational settling of olivine crystals in a large melt body. Artuby ridge, just outside the SW portion of Séítah and stratigraphically just above it, contains up to 60% pyroxene. The upper portions of the Máaz formation are more enriched in plagioclase, with the uppermost Ch’al member having the most evolved composition, along with the Content member, pitted rocks directly overlying the main cumulate portion of Séítah. After exploring the floor, Perseverance drove to the delta formation and began a walk-about style of observations starting at Enchanted Lake, just below an arm of the delta formation, and then moving into Hawksbill Gap, climbing 18 m in elevation between Devil’s Tanyard, Sunset Hill, and Hogwallow flats. Delta compositions initially displayed higher phyllosilicate contents, identified by absorptions at 1.4, 1.9, and 2.3 µm, and by higher LIBS H peak areas. Farther up, compositions changed to sulfur-bearing in lower locations within the continuous fine-grained light-toned strata (e.g., Pignut Mountain, Sol 463) and carbonate-rich in upper strata. Veins were observed, consisting of Mg-Fe carbonate (Elder Ridge, Sol 459) and anhydrite (Reid’s Gap, Sol 466). The sulfates suggest precipitation of these salts at a later stage, as the lake was evaporating. Carbonates and sulfates in veins in different locations indicate that groundwater was active in the lithified sediments and had significantly different chemistry at different intervals

Jezero Crater Floor and Delta Chemistry and Mineralogy Observed by SuperCam in the First 1.5 Years of the Perseverance Rover Mission

International audienc