Mission: To advance our understanding of the Solar System through the: i) development of cutting-edge analytical techniques; ii) analysis of terrestrial samples and planetary analogs; iii) maturation of pioneering new technologies; and, iv) definition of innovative planetary mission concepts.
Current Research Projects
Dead or Never Alive!
Organic Matter in Terrestrial Samples and Meteorites
Luke and Katie
For upcoming life detection missions, such as the Rosalind Franklin ExoMars Rover, there is a critical need to evaluate the differences between abiotic and degraded biotic organic matter. Using a spaceflight relevant technique, laser desorption mass spectrometry (LDMS), with an Orbitrap high-resolution mass analyzer, we can test the biogenicity of organic matter in geologic samples. Carbonaceous chondrites (CC) are carbon rich meteorites that are a source of abiotic organic matter on bodies such as Mars. The dominant component of abiotic organic matter in CCs is a complex macromolecular structure termed insoluble organic matter (IOM). The bulk composition of this IOM is remarkably similar to terrestrial kerogen, a biogenically degraded organic product and present in organic rich shales. Kerogen is the largest reservoir of organic matter here on Earth represents a widespread geochemical fossil if life exists elsewhere. This work aims to understand how the organic diversity, structure, and distribution in degraded biological matter differs from complex abiotic matter via LDMS to assign biogenicity off world.
Mineralogical Effects on Organic Detectability
Maddy and Meridian
Searching for signs of life is a high priority for future space exploration. Laser desorption mass spectrometry (LDMS) is a technique that will be used by future missions to Mars and Titan to search signs of life in the form of large organic molecules. However, the ability to detect organic molecules with this technique may be affected by the geology and mineralogy of a target sample. This study focuses on exploring how different minerals found on Mars (Raith), and salts on Enceladus (McCall) affect our ability to detect lipids, amino acids, and nucleic acids with LDMS. Results have shown that different minerals will impact the limits of detection of cholesterol, and salts may have varying impacts on the limit of detection of amino acids and nucleic acids. The cause for the variations in organics’ limits of detection is still being investigated, but may are likely related to physical and chemical properties of the minerals.
Machine Learning for Planetary Science
Maddy, Sourabh, and Luke
Laser Desorption Mass Spectrometry (LDMS), an analytical technique capable of measuring the inorganic and organic composition of solid samples in situ, enables the identification of spatial correlations between geological phases and chemical biosignatures, such as complex organic compounds. Due to rapid experimental cadences (generally > 1Hz) and limited sample destruction (typically <50 nm of material is removed per laser shot), LDMS protocols can produce hundreds of spectra during the analysis of a single mineral grain. Because each spectrum may contain hundreds of unique peaks, human interpretation is challenging. Thus, LDMS techniques provide an ideal case study for developing machine learning (ML) applications. M-CLASS lab is currently using ML techniques for mineralogical identification via LDMS (Raith), lithological identification using geochemistry (Shubham), and differentiating abiotic and biotic samples (Andrews).
Quantitative Laser Desorption Orbitrap Mass Spectrometry
Soumya, Maddy, Oya, Luke
In the M-CLASS Lab at the University of Maryland, we explore, optimize, and characterize the capacity of LDMS techniques, as enabled by a UV laser interfaced to an Orbitrap mass analyzer, to deliver quantitative measurements of non-traditional stable isotope ratios (e.g., Ti), as well as absolute abundances of major, minor, and select trace elements (e.g., Cr). We also investigate the effects of mineralogy on the sensitivity, and by extension detection limits, of organic compounds (e.g., cholesterol). A comparison between commercial systems and instruments miniaturized for deployment in the field provides insights into fundamental capabilities/limitations versus those specific to the analytical platform. To date, we have measured select isotopic ratios with (sub-)permil-level precision, quantified major and minor element abundances to within 10% of ground-truth, and observed detection limits for lipids that vary by orders of magnitude based on the mineral adsorbent. However, significant challenges remain, including (but not limited to): i) controlling ion injection to limit space-charge effects within the mass analyzer; ii) modeling dephasing (and recovery) of ion packets within the Orbitrap during extended transients; iii) reducing detection limits and accessing a wider range of trace elements; and, iv) reducing shot-to-shot variations in signal intensities, promoting higher precision/accuracy measurements.
AROMA, CORALS, and CRATER Instruments
Oya, Soumya, and Luke
These spaceflight LDMS instruments are in development to conduct: 1) chemical imaging of geologic material via laser microprocessing; 2) measurements of trace levels of organic compounds, molecular fragments, and inorganic mineralogical indicators; 3) high-precision determinations of abundance patterns and isotopic ratios. We are developing a high-fidelity engineering test unit with applications to icy worlds (CORALS - Kawashima) and the moon (CRATER - Ray) that will meet the form/fit/function of the flight model, deliver full science performance, and survive random vibration and dry heat microbial reduction (DHMR). By leveraging a heritage linear ion trap mass analyzer, the AROMA instrument (Andrews) reproduces the functionality of the MOMA flight instrument (on the ExoMars rover), but with an extended mass range (up to 2000 Da) and more capable laser (higher energy plus precision attenuation). Equipped with an Orbitrap analyzer adapted for spaceflight, referred to as the CosmOrbitrap by the consortium of French laboratories responsible for its development, the AROMA instrument delivers higher mass resolution and accuracy than any instrument previously flown to date.
PLASMA: Pulsed Laser Ablation Sampling and Mass Analysis
Ben and Maddy
Previous in situ analyses on planetary surfaces have provided major and minor element data, but are challenged to deliver chemical data at the ppm level and/or isotope ratios. In laboratory settings, trace chemical and isotopic analysis via inductively coupled plasma mass spectrometer (ICPMS) has become the dominant analytical method. We have designed, built, and demonstrated a novel plasma source that requires significantly less power (<25 W, compared to 1400 W) and gas (<0.2 L/min, compared to 16+L/min) than to commercial systems. To date, the prototype ICPMS is providing mass spectra of simple analytes. Results from further instrumental developments and analysis experiments will be reported on, as well as our tests of the laser ablation system. We will also report on the application of this instrument at potential Lunar landing sites, our proposed analytical campaign, and the targeted research goals. (Farcy et al, 2021)
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