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All sourcesNASA NTRSDOE OSTI
NASA NTRS1995

Organic Compounds Produced by Photolysis of Realistic Interstellar and Cometary Ice Analogs Containing Methanol

The InfraRed (IR) spectra of UltraViolet (UV) and thermally processed, methanol-containing interstellar / cometary ice analogs at temperatures from 12 to 300 K are presented. Infrared spectroscopy, H-1 and C-13 Nuclear Magnetic Resonance (NMR) spectroscopy, and gas chromatography-mass spectrometry indicate that CO (carbon monoxide), CO2 (carbon dioxide), CH4 (methane), HCO (the formyl radical), H2CO (formaldehyde), CH3CH2OH (ethanol), HC([double bond]O)NH2 (formamide), CH3C([double bond]O)NH2 (acetamide), and R[single bond]C[triple bond]N (nitriles) are formed. In addition, the organic materials remaining after photolyzed ice analogs have been warmed to room temperature contain (in rough order of decreasing abundance), (1) hexamethylenetetramine (HMT, C6H12N4), (2) ethers, alcohols, and compounds related to PolyOxyMethylene (POM, ([single bond]CH2O[single bond](sub n)), and (3) ketones (R[single bond]C([double bond]O)[single bond]R') and amides (H2NC([double bond]O)[single bond]R). Most of the carbon in these residues is thought to come from the methanol in the original ice. Deuterium and C-13 isotopic labeling demonstrates that methanol is definitely the source of carbon in HMT. High concentrations of HMT in interstellar and cometary ices could have important astrophysical consequences. The ultraviolet photolysis of HMT frozen in H2O ice readily produces the 'XCN' band observed in the spectra of protostellar objects and laboratory ices, as well as other nitriles. Thus, HMT may be a precursor of XCN and a source of CN in comets and the interstellar medium. Also, HMT is known to hydrolyze under acidic conditions to yield ammonia, formaldehyde, and amino acids. Thus, HMT may be a significant source of prebiogenic compounds on asteroidal parent bodies. A potential mechanism for the radiative formation of HMT in cosmic ices is outlined.

Bernstein, Max P.↗
NASA NTRS2004

The AstroBiology Explorer (ABE) Mission Concept

Infrared spectroscopy in the 2.5-16 micron range is a principle means by which organic compounds can be detected and identified in space via their vibrational transitions. Ground-based, airborne, and spaceborne IR spectral studies have already demonstrated that a significant fraction of the carbon in the interstellar medium (ISM) resides in the form of complex organic molecular species. Unfortunately, neither the distribution of these materials nor their genetic and evolutionary relationships with each other or their environments are well understood. The Astrobiology Explorer (ABE) is a MIDEX mission concept currently under study by a team of partners: NASA's Ames Research Center, Ball Aerospace and Technologies Corporation, and the Jet Propulsion Laboratory. ABE will conduct IR spectroscopic observations to address outstanding important problems in astrobiology, astrochemistry, and astrophysics. The core observational program would make fundamental scientific progress in understanding (1) The evolution of ices and organic matter in dense molecular clouds and young forming stellar systems, (2) The chemical evolution of organic molecules in the ISM as they transition from AGB outflows to planetary nebulae to the general diffuse ISM to HII regions and dense clouds, (3) The distribution of organics in the diffuse ISM, (4) The nature of organics in the Solar System (in comets, asteroids, satellites), and (5) The nature and distribution of organics in local galaxies. The technical considerations of achieving these science objectives in a MIDEX-sized mission will be presented.

Sandford, Scott A.↗
NASA NTRS2001

The AstroBiology Explorer (ABE) MIDEX Mission Concept: Exploring the Links Between the Interstellar Medium and Meteorites

Infrared spectroscopy in the 2.5-16 micron range is a principle means by which organic compounds can be detected and identified in space via their vibrational transitions. Ground-based, airborne, and spaceborne IR spectral studies have already demonstrated that a significant fraction of the carbon in the interstellar medium (ISM) resides in the form of complex organic molecular species. Furthermore, the presence of D-enriched organics in meteorites suggests that a portion of these materials survives incorporation into protosolar nebulae. Unfortunately, neither the distribution of these materials nor their genetic and evolutionary relationships with each other or their environments are well understood. The Astrobiology Explorer (ABE) is a MIDEX mission concept currently under study at NASA's Ames Research Center in collaboration with Ball Aerospace and Technologies Corporation. ABE will conduct IR spectroscopic observations to address outstanding important problems in astrobiology, astrochemistry, and astrophysics. The core observational program would make fundamental scientific progress in understanding (1) the evolution of ices and organic matter in dense molecular clouds and young forming stellar systems, (2) the chemical evolution of organic molecules in the ISM as they transition from AGB outflows to planetary nebulae to the general diffuse ISM to HII regions and dense clouds, (3) the distribution of organics in the diffuse ISM, (4) the nature of organics in the Solar System (in comets, asteroids, satellites), and (5) the nature and distribution of organics in local galaxies. In addition, ABE will attempt to detect and quantify deuterium enrichments in a select set of these materials and environments. This should assist both with understanding the chemical processes that occur in these environments and with establishing any links that exist between interstellar and meteoritic organics.

Sandford, Scott A.↗
NASA NTRS2017

The Astromaterials X-Ray Computed Tomography Laboratory at Johnson Space Center

The Astromaterials Acquisition and Curation Office at NASA's Johnson Space Center (hereafter JSC curation) is the past, present, and future home of all of NASA's astromaterials sample collections. JSC curation currently houses all or part of nine different sample collections: (1) Apollo samples (1969), (2) Lunar samples (1972), (3) Antarctic meteorites (1976), (4) Cosmic Dust particles (1981), (5) Microparticle Impact Collection (1985), (6) Genesis solar wind atoms (2004); (7) Stardust comet Wild-2 particles (2006), (8) Stardust interstellar particles (2006), and (9) Hayabusa asteroid Itokawa particles (2010). Each sample collection is housed in a dedicated clean room, or suite of clean rooms, that is tailored to the requirements of that sample collection. Our primary goals are to maintain the long-term integrity of the samples and ensure that the samples are distributed for scientific study in a fair, timely, and responsible manner, thus maximizing the return on each sample. Part of the curation process is planning for the future, and we also perform fundamental research in advanced curation initiatives. Advanced Curation is tasked with developing procedures, technology, and data sets necessary for curating new types of sample collections, or getting new results from existing sample collections [2]. We are (and have been) planning for future curation, including cold curation, extended curation of ices and volatiles, curation of samples with special chemical considerations such as perchlorate-rich samples, and curation of organically- and biologically-sensitive samples. As part of these advanced curation efforts we are augmenting our analytical facilities as well. A micro X-Ray computed tomography (micro-XCT) laboratory dedicated to the study of astromaterials will be coming online this spring within the JSC Curation office, and we plan to add additional facilities that will enable nondestructive (or minimally-destructive) analyses of astromaterials in the near future (micro-XRF, confocal imaging Raman Spectroscopy). These facilities will be available to: (1) develop sample handling and storage techniques for future sample return missions; (2) be utilized by PET for future sample return missions; (3) be used for retroactive PET (Positron Emission Tomography)-style analyses of our existing collections; and (4) for periodic assessments of the existing sample collections. Here we describe the new micro-XCT system, as well as some of the ongoing or anticipated applications of the instrument.

Zeigler, R. A.↗
NASA NTRS2017

The Astromaterials X-Ray Computed Tomography Laboratory at Johnson Space Center

The Astromaterials Acquisition and Curation Office at NASA's Johnson Space Center (hereafter JSC curation) is the past, present, and future home of all of NASA's astromaterials sample collections. JSC curation currently houses all or part of nine different sample collections: (1) Apollo samples (1969), (2) Lunar samples (1972), (3) Antarctic meteorites (1976), (4) Cosmic Dust particles (1981), (5) Microparticle Impact Collection (1985), (6) Genesis solar wind atoms (2004); (7) Stardust comet Wild-2 particles (2006), (8) Stardust interstellar particles (2006), and (9) Hayabusa asteroid Itokawa particles (2010). Each sample collection is housed in a dedicated clean room, or suite of clean rooms, that is tailored to the requirements of that sample collection. Our primary goals are to maintain the long-term integrity of the samples and ensure that the samples are distributed for scientific study in a fair, timely, and responsible manner, thus maximizing the return on each sample. Part of the curation process is planning for the future, and we also perform fundamental research in advanced curation initiatives. Advanced Curation is tasked with developing procedures, technology, and data sets necessary for curating new types of sample collections, or getting new results from existing sample collections [2]. We are (and have been) planning for future curation, including cold curation, extended curation of ices and volatiles, curation of samples with special chemical considerations such as perchlorate-rich samples, and curation of organically- and biologically-sensitive samples. As part of these advanced curation efforts we are augmenting our analytical facilities as well. A micro X-Ray computed tomography (micro-XCT) laboratory dedicated to the study of astromaterials will be coming online this spring within the JSC Curation office, and we plan to add additional facilities that will enable nondestructive (or minimally-destructive) analyses of astromaterials in the near future (micro-XRF, confocal imaging Raman Spectroscopy). These facilities will be available to: (1) develop sample handling and storage techniques for future sample return missions; (2) be utilized by PET for future sample return missions; (3) be used for retroactive PET (Positron Emission Tomography)-style analyses of our existing collections; and (4) for periodic assessments of the existing sample collections. Here we describe the new micro-XCT system, as well as some of the ongoing or anticipated applications of the instrument.

Zeigler, R. A.↗
NASA NTRS1993

Infrared spectroscopy of Jupiter and Saturn

Infrared spectroscopy provides unique insights into the chemistry and dynamics of the atmospheres of Jupiter, Saturn, and Titan. In 1991 we obtained data at J, H, K, and M and made repeated observations of Titan's albedo as the satellite orbited Saturn. The J albedo is 12% +/- 3% greater than the albedo measured in 1979; the H and K albedos are the same. There was no evidence for variations at any wavelength over the eastern half of Titan's orbit. We also obtained low resolution (R=50) spectra of Titan between 3.1 and 5.1 microns. The spectra contain evidence for CO and CH3D absorptions. Spectra of Callisto and Ganymede in the 4.5 micron spectral region are featureless and give albedos of 0.08 and 0.04 respectively. If Titan's atmosphere is transparent near 5 microns, its surface albedo there is similar to Callisto's. In 1992 and 1993 we obtained further spectroscopic data of Titan with the UKIRT CGS4 spectrometer. We discovered two unexpected and unexplained spectral features in the 3-4 micron spectrum of Titan. An apparent emission feature near the 3 micron (nu sub 3) band of methane indicated temperatures higher than known to be present in Titan's upper stratosphere and may be caused by unexpected non-LTE emission. An absorption feature near 3.47 microns may be caused by absorption in solid grains or aerosols in Titan's clouds. The feature is similar but not identical to organics in the interstellar matter and in comets.

Knacke, Roger F.↗
NASA NTRS2023

Soluble Organic Matter Molecular Atlas of Ryugu Reveals Cold Hydrothermalism on C-Type Asteroid Parent Body

The sample from the near-Earth carbonaceous asteroid (162173) Ryugu is analyzed in the context of carbonaceous meteorites soluble organic matter. The analysis of soluble molecules of samples collected by the Hayabusa2 spacecraft shines light on an extremely high molecular diversity on the C-type asteroid. Sequential solvent extracts of increasing polarity of Ryugu samples are analyzed using mass spectrometry with complementary ionization methods and structural information confirmed by nuclear magnetic resonance spectroscopy. Here we show a continuum in the molecular size and polarity, and no organomagnesium molecules are detected, reflecting a low temperature and water-rich environment on the parent body approving earlier mineralogical and chemical data. High abundance of sulfidic and nitrogen rich compounds as well as high abundance of ammonium ions confirm the water processing. Polycyclic aromatic hydrocarbons are also detected in a structural continuum of carbon saturations and oxidations, implying multiple origins of the observed organic complexity, thus involving generic processes such as earlier carbonization and serpentinization with successive low temperature aqueous alteration.

Asteroids, comets and Kuiper belt↗
NASA NTRS1997

Continuing Studies in Support of Ultraviolet Observations of Planetary Atmospheres

This program was a one-year extension of an earlier Planetary Atmospheres program grant, covering the period 1 August 1996 through 30 September 1997. The grant was for supporting work to complement an active program observing planetary atmospheres with Earth-orbital telescopes, principally the Hubble Space Telescope (HST). The recent concentration of this work has been on HST observations of Jupiter's upper atmosphere and aurora, but it has also included observations of Io, serendipitous observations of asteroids, and observations of the velocity structure in the interplanetary medium. The observations of Jupiter have been at vacuum ultraviolet wavelengths, including imaging and spectroscopy of the auroral and airglow emissions. The most recent HST observations have been at the same time as in situ measurements made by the Galileo orbiter instruments, as reflected in the meeting presentations listed below. Concentrated efforts have been applied in this year to the following projects: The analysis of HST WFPC 2 images of Jupiter's aurora, including the Io footprint emissions. We have performed a comparative analysis of the lo footprint locations with two magnetic field models, studied the statistical properties of the apparent dawn auroral storms on Jupiter, and found various other repeated patterns in Jupiter's aurora. Analysis and modeling of airglow and auroral Ly alpha emission line profiles from Jupiter. This has included modeling the aurora] line profiles, including the energy degradation of precipitating charged particles and radiative transfer of the emerging emissions. Jupiter's auroral emission line profile is self-absorbed, since it is produced by an internal source, and the resulting emission with a deep central absorption from the overlying atmosphere permits modeling of the depth of the emissions, plus the motion of the emitting layer with respect to the overlying atmospheric column from the observed Doppler shift of the central absorption. By contrast the airglow emission line, which is dominated by resonant scattering of solar emission, has no central absorption, but displays rapid time variations and broad wings, indicative of a superthermal component (or corona) in Jupiter's upper atmosphere. Modeling of the observed motions of the plumes produced after the impacts of the fragments of Comet S/L-9 with Jupiter in July 1994, from the HST WFPC 2 imaging series.

Clark, John↗
NASA NTRS2012

Analysis of Direct Samples of Early Solar System Aqueous Fluids

Over the past three decades we have become increasingly aware of the fundamental importance of water, and aqueous alteration, on primitive solar-system bodies. Some carbonaceous and ordinary chondrites have been altered by interactions with liquid water within the first 10 million years after formation of their parent asteroids. Millimeter to centimeter-sized aggregates of purple halite containing aqueous fluid inclusions were found in the matrix of two freshly-fallen brecciated H chondrite falls, Monahans (1998, hereafter simply "Monahans") (H5) and Zag (H3-6) (Zolensky et al., 1999; Whitby et al., 2000; Bogard et al., 2001) In order to understand origin and evolution of the aqueous fluids inside these inclusions we much measure the actual fluid composition, and also learn the O and H isotopic composition of the water. It has taken a decade for laboratory analytical techniques to catch up to these particular nanomole-sized aqueous samples. We have recently been successful in (1) measuring the isotopic composition of H and O in the water in a few fluid inclusions from the Zag and Monahans halite, (2) mineralogical characterization of the solid mineral phases associated with the aqueous fluids within the halite, and (3) the first minor element analyses of the fluid itself. A Cameca ims-1270 equipped with a cryo-sample-stage of Hokkaido University was specially prepared for the O and H isotopic measurements. The cryo-sample-stage (Techno. I. S. Corp.) was cooled down to c.a. -190 C using liquid nitrogen at which the aqueous fluid in inclusions was frozen. We excavated the salt crystal surfaces to expose the frozen fluids using a 15 keV Cs+ beam and measured negative secondary ions. The secondary ions from deep craters of approximately 10 m in depth emitted stably but the intensities changed gradually during measurement cycles because of shifting states of charge compensation, resulting in rather poor reproducibility of multiple measurements of standard fluid inclusions of +/- 90 0/00(2 sigma) for delta D, and +/- 29 0/00 (2 sigma) for delta O-18. On the other hand, the reproducibility of Delta O-17 is plus or minus 8 /00 (2 sigma ) because the observed variations of isotope ratios follow a mass dependent fractionation law. Variations of delta D of the aqueous fluids range over sog,a 330(90; 2 sigma ) to +1200(90) 0/00 for Monahans and delta 300(96) 0/00 to +90(98)0/00 for Zag. Delta O-17 of aqueous fluids range over delta 16(22) 0/00 to +18(10) 0/00 for Monahans and +3(10) 0/00 to +27(11) 0/00 for Zag. These variations are larger than the reproducibility of standard analyses and suggest that isotope equilibria were under way in the fluids before trapping into halite. The mean values of delta D and Delta O-17 are +290 0/00 and +9 0/00, respectively. The mean values and the variations of these fluids are different from the representative values of ordinary chondrites, verifying our working hypothesis that the fluid inclusion-bearing halites were not indigenous to the H chondrite parent-asteroid but rather represent exogenous material delivered onto the asteroid from a separate cryovolcanically-active body. This initial isotopic work has demonstrated the feasibility of the measurements, but also revealed sample processing and analytical shortcomings that are now being addressed. Examination of solid mineral inclusions within Monahans and Zag halite grains by confocal Raman spectroscopy at the Carnegie Geophysical Laboratory has revealed them to be metal, magnetite, forsteritic olivine (Fo.98), macromolecular carbon (MMC), pyroxenes, feldspar with Raman spectral affinity to anorthoclase and, probably, fine-grained lepidocrocite (FeO(OH)). In addition, one inclusion features aliphatic material with Raman spectral features consistent with a mixture of short-chain aliphatic compounds. We have initiated analyses of the bulk composition of the fluids within the inclusions in Zag and Monahans halites at Virginia Tech by LA ICPMS using angilent 7500ce quadrupole ICPMS and a Lambda Physik GeoLas 193 nm excimer laser ablation system. Preliminary results reveal that the inclusion aqueous fluids contain highly charged cations of Ca, Mg and Fe. The minerals and compounds discovered thus far within Monahans/Zag halites are indicative of an originating body at least partly composed of unequilibrated anhydrous materials (high Fo olivine, pyroxenes, feldspars, possibly the metal) which were subjected to aqueous alteration (the halite parent brine) and containing a light organic component (the short-chain aliphatic compounds). This material was ejected from the originating body with little or no disruption, as evidenced with the presence of fluid inclusions. An actively geysering body similar to modern Enceladus (Postberg et al., 2011) may be a reasonable analogue in this respect. Also, the originating body should have been within close proximity to the H chondrite parent in order to generate the number of halite grains seen in Monahans and Zag. Other candidates for Monahans/Zag halite parent bodie(s) may include a young Ceres with its possible liquid ocean, or Main Belt comets.

Zolensky, Michael E.↗
NASA NTRSDate not supplied

Photonic Integrated Circuit TUned for Reconnaissance and Exploration (PICTURE)

The mid-infrared (MIR) spectral range (3-5 μm) is of particular interest for remotely sensing gaseous molecules such as H2O, CO2, CH4, N2O, CO, NH3, and other compounds. The infrared spectra of planets, moons, comets, and asteroids are rich in information, including gas composition and surface mineralogy. Significant advances in technology have emerged for ground-based telescopes, including the higher spectral resolution permitted by cross-dispersed instruments and heterodyne techniques. New technologies offer the opportunity to break this barrier, by using solid- state photonics. In the past three years, under the NASA ROSES PICASSO program, we have been developing key components for a revolutionary MIR spectrometer: Photonic Integrated Circuit TUned for Reconnaissance and Exploration (PICTURE), which is based on integrated photonics technology that offers ultra-small size, weight, and power (SWaP) with non-moving parts and low cost for future planetary missions. In this paper, we will describe our science and technology development progress leading to demonstrating the concept and functionalities of the PICTURE instrument. The photonic integrated circuit spectrometer (PICS) of the PICTURE instrument uses an integrated heterodyne detection scheme to significantly reduce SWaP and improve sensitivity. Our program goals are to advance the building blocks needed for the PICS, which include arrayed waveguide gratings (AWGs), quantum cascade lasers (QCLs) as local oscillators, and quantum cascade detectors (QCDs) as heterodyne detectors. In addition, we are leveraging a NASA SBIR program to develop the toolsets needed to fabricate MIR photonics lanterns (PL). The PL is a critical component that enables PICTURE to bring a signal from the collecting telescope to the PICS, which requires single optical mode inputs. PICTURE focuses on the CO spectral band at 4.6-4.8 μm that is of key importance to cometary science. We also continue to explore future instrument concepts that exploit the broad wavelength potential of the PICS design to perform spectroscopy spanning the full MIR and longwave IR (LWIR) bands. This will have wide applicability in planetary science, for example, to probe the strongest CO2, H2O, and CH4 transitions that are difficult (CH4) or impossible (CO2, H2O) to detect using Earth-based telescopes due to atmospheric opacity. Each integrated-photonics-spectrometer chip will feature a single heterodyne room-temperature laser with a wide wavelength tuning range, or multiple local-oscillator lasers for much broader spectral coverage. The fully developed PICTURE instrument will provide a cost-effective, high-resolution spectrometer for future space applications.

Anthony W Yu↗
NASA NTRSDate not supplied

Photonic Integrated Circuit TUned for Reconnaissance and Exploration (PICTURE)

The mid-infrared (MIR) spectral range (3-5 μm) is of particular interest for remotely sensing gaseous molecules such as H2O, CO2, CH4, N2O, CO, NH3, and other compounds. The infrared spectra of planets, moons, comets, and asteroids are rich in information, including gas composition and surface mineralogy. Significant advances in technology have emerged for ground-based telescopes, including the higher spectral resolution permitted by cross-dispersed instruments and heterodyne techniques. New technologies offer the opportunity to break this barrier, by using solid-state photonics. In the past three years, under the NASA ROSES PICASSO program, we have been developing key components for a revolutionary MIR spectrometer: Photonic Integrated Circuit TUned for Reconnaissance and Exploration (PICTURE), which is based on integrated photonics technology that offers ultra-small size, weight, and power (SWaP) with non-moving parts and low cost for future planetary missions. In this paper, we will describe our science and technology development progress leading to demonstrating the concept and functionalities of the PICTURE instrument. The photonic integrated circuit spectrometer (PICS) of the PICTURE instrument uses an integrated heterodyne detection scheme to significantly reduce SWaP and improve sensitivity. Our program goals are to advance the building blocks needed for the PICS, which include arrayed waveguide gratings (AWGs), quantum cascade lasers (QCLs) as local oscillators, and quantum cascade detectors (QCDs) as heterodyne detectors. In addition, we are leveraging a NASA SBIR program to develop the toolsets needed to fabricate MIR photonics lanterns (PL). The PL is a critical component that enables PICTURE to bring a signal from the collecting telescope to the PICS, which requires single optical mode inputs. PICTURE focuses on the CO spectral band at 4.6-4.8 μm that is of key importance to cometary science. We also continue to explore future instrument concepts that exploit the broad wavelength potential of the PICS design to perform spectroscopy spanning the full MIR and longwave IR (LWIR) bands. This will have wide applicability in planetary science, for example, to probe the strongest CO2, H2O, and CH4 transitions that are difficult (CH4) or impossible (CO2, H2O) to detect using Earth-based telescopes due to atmospheric opacity. Each integrated-photonics-spectrometer chip will feature a single heterodyne room-temperature laser with a wide wavelength tuning range, or multiple local-oscillator lasers for much broader spectral coverage. The fully developed PICTURE instrument will provide a cost-effective, high-resolution spectrometer for future space applications.

Anthony W Yu↗
NASA NTRSDate not supplied

Photonic Integrated Circuit TUned for Reconnaissance and Exploration (PICTURE)

The mid-infrared (MIR) spectral range (3-5 μm) is of particular interest for remotely sensing gaseous molecules such as H2O, CO2, CH4, N2O, CO, NH3, and other compounds. The infrared spectra of planets, moons, comets, and asteroids are rich in information, including gas composition and surface mineralogy. Significant advances in technology have emerged for ground-based telescopes, including the higher spectral resolution permitted by cross-dispersed instruments and heterodyne techniques. New technologies offer the opportunity to break this barrier, by using solid-state photonics. In the past three years, under the NASA ROSES PICASSO program, we have been developing key components for a revolutionary MIR spectrometer: Photonic Integrated Circuit TUned for Reconnaissance and Exploration (PICTURE), which is based on integrated photonics technology that offers ultra-small size, weight, and power (SWaP) with non-moving parts and low cost for future planetary missions. In this paper, we will describe our science and technology development progress leading to demonstrating the concept and functionalities of the PICTURE instrument. The photonic integrated circuit spectrometer (PICS) of the PICTURE instrument uses an integrated heterodyne detection scheme to significantly reduce SWaP and improve sensitivity. Our program goals are to advance the building blocks needed for the PICS, which include arrayed waveguide gratings (AWGs), quantum cascade lasers (QCLs) as local oscillators, and quantum cascade detectors (QCDs) as heterodyne detectors. In addition, we are leveraging a NASA SBIR program to develop the toolsets needed to fabricate MIR photonics lanterns (PL). The PL is a critical component that enables PICTURE to bring a signal from the collecting telescope to the PICS, which requires single optical mode inputs. PICTURE focuses on the CO spectral band at 4.6-4.8 μm that is of key importance to cometary science. We also continue to explore future instrument concepts that exploit the broad wavelength potential of the PICS design to perform spectroscopy spanning the full MIR and longwave IR (LWIR) bands. This will have wide applicability in planetary science, for example, to probe the strongest CO2, H2O, and CH4 transitions that are difficult (CH4) or impossible (CO2, H2O) to detect using Earth-based telescopes due to atmospheric opacity. Each integrated-photonics-spectrometer chip will feature a single heterodyne room-temperature laser with a wide wavelength tuning range, or multiple local-oscillator lasers for much broader spectral coverage. The fully developed PICTURE instrument will provide a cost-effective, high-resolution spectrometer for future space applications.

Anthony W. Yu↗
NASA NTRS1994

Infrared spectroscopy of Jupiter and Saturn

Infrared spectroscopy provides unique insights into the chemistry and dynamics of the atmospheres of Jupiter and Saturn -- and of Titan, the enigmatic satellite of Saturn. The 5 micron spectral region of these objects is transparent to deep levels, and is therefore particularly useful for the identification of molecules in the deep atmosphere at very low (parts per billion) concentrations. In 1991 we obtained data at J, H, K, and M and made repeated observations of Titan's albedo as the satellite orbited Saturn. The J albedo is 12 + -3% greater than the albedo measured in 1979; the H and K albedos are the same. There was no evidence for variations at any wavelength over the eastern half of Titan's orbit. We also obtained low resolution (R = 50) spectra of Titan between 3.1 and 5.1 microns. The spectra contain evidence for CO and CH3D absorptions. Spectra of Callisto and Ganymede in the 4.5 micron spectral region are featureless and give albedos of 0.08 and 0.04 respectively. If Titan's atmosphere is transparent near 5 microns, its surface albedo there is similar to Callisto's. In 1992 and 1993 we obtained further spectroscopic data of Titan with the UKIRT CGS4 spectrometer. We discovered two unexpected and unexplained spectral features in the 3-4 micron /spectrum of Titan. An apparent emission feature near the 3 micron (nu3) band of methane indicates temperatures higher than known to be present in Titan's upper stratosphere and may be caused by unexpected non-LTE emission. An absorption feature near 3.47 microns may be caused by absorption in solid grains or aerosol's in Titan's clouds. The feature is similar, but not identical to organics in the interstellar matter and in comets.

Knacke, Roger F.↗
NASA NTRS2017

Molecular Composition Analysis of Distant Targets

This document is the Final Report for NASA Innovative Advanced Concepts (NIAC) Phase I Grant 15-NIAC16A-0145, titled Molecular Composition Analysis of Distant Targets. The research was focused on developing a system concept for probing the molecular composition of cold solar system targets, such as Asteroids, Comets, Planets and Moons from a distant vantage, for example from a spacecraft that is orbiting the target (Hughes et al., 2015). The orbiting spacecraft is equipped with a high-power laser, which is run by electricity from photovoltaic panels. The laser is directed at a spot on the target. Materials on the surface of the target are heated by the laser beam, and begin to melt and then evaporate, forming a plume of asteroid molecules in front of the heated spot. The heated spot glows, producing blackbody illumination that is visible from the spacecraft, via a path through the evaporated plume. As the blackbody radiation from the heated spot passes through the plume of evaporated material, molecules in the plume absorb radiation in a manner that is specific to the rotational and vibrational characteristics of the specific molecules. A spectrometer aboard the spacecraft is used to observe absorption lines in the blackbody signal. The pattern of absorption can be used to estimate the molecular composition of materials in the plume, which originated on the target. Focusing on a single spot produces a borehole, and shallow subsurface profiling of the targets bulk composition is possible. At the beginning of the Phase I research, the estimated Technology Readiness Level (TRL) of the system was TRL-1. During the Phase I research, an end-to-end theoretical model of the sensor system was developed from first principles. The model includes laser energy and optical propagation, target heating, melting and evaporation of target material, plume density, thermal radiation from the heated spot, molecular cross section of likely asteroid materials, and estimation of the absorption profile at a distant spectrometer. Results obtained by executing simulations based on the model provide compelling evidence that the concept of remote laser evaporative molecular absorption spectroscopy is feasible. In this document, technical details of the model are presented, and results of simulations are described that indicate the utility of the proposed sensor system. Additionally, an asteroid rendezvous mission is analyzed, with a survey of system requirements to accomplish molecular composition analysis of the asteroid. Based on positive theoretical results obtained during Phase I, the estimated TRL of the system is now TRL-2. This document also describes potential future research and experimentation that could push the system to TRL-4 within 2 years. Steps required for construction of a laboratory prototype are described. An experiment to test predictions of the theory is described, based on the laboratory prototype setup.

asteroid↗
NASA NTRS2014

Coordinated Microanalyses of Seven Particles of Probable Interstellar Origin from the Stardust Mission

Stardust, a NASA Discovery-class mission, was the first sample-return mission to return solid samples from beyond the Moon. Stardust was effectively two missions in one spacecraft: it returned the first materials from a known primitive solar system body, the Jupiter-family comet Wild 2; Stardust also returned a collector that was exposed to the contemporary interstellar dust stream for 200 days during the interplanetary cruise. Both collections present severe technical challenges in sample preparation and in analysis. By far the largest collection is the cometary one: approximately 300 micro g of material was returned from Wild 2, mostly consisting of approx. 1 ng particles embedded in aerogel or captured as residues in craters on aluminum foils. Because of their relatively large size, identification of the impacts of cometary particles in the collection media is straightforward. Reliable techniques have been developed for the extraction of these particles from aerogel. Coordinated analyses are also relatively straightforward, often beginning with synchrotron-based x-ray fluorescence (S-XRF), X-ray Absorption Near-Edge Spectoscopy (XANES) and x-ray diffraction (S-XRD) analyses of particles while still embedded in small extracted wedges of aerogel called ``keystones'', followed by ultramicrotomy and TEM, Scanning Transmission X-ray Microscopy (STXM) and ion microprobe analyses (e.g., Ogliore et al., 2010). Impacts in foils can be readily analyzed by SEM-EDX, and TEM analysis after FIB liftout sample preparation. In contrast, the interstellar dust collection is vastly more challenging. The sample size is approximately six orders of magnitude smaller in total mass. The largest particles are only a few pg in mass, of which there may be only approx.10 in the entire collection. The technical challenges, however, are matched by the scientific importance of the collection. We formed a consortium carry out the Stardust Interstellar Preliminary Examination (ISPE) to carry out an assessment of this collection, partly in order to characterize the collection in sufficient detail so that future investigators could make well-informed sample requests. The ISPE is the sixth PE on extraterrestrial collections carried out with NASA support. Some of the basic questions that we asked were: how many impacts are there in the collector, and what fraction of them have characteristics consistent with extraterrestrial materials? What is the elemental composition of the rock-forming elements? Is there crystalline material? Are there organics? Here we present coordinated microanalyses of particles captured in aerogel, using S-FTIR, S-XRF, STXM, S-XRD; and coordinated microanalyses of residues in aluminum foil, using SEMEDX, Auger spectroscopy, STEM, and ion microprobe. We discuss a novel approach that we employed for identification of tracks in aerogel, and new sample preparation techniques developed during the ISPE. We have identified seven particles - three in aerogel and four in foils - that are most consistent with an interstellar origin. The seven particles exhibit a large diversity in elemental composition. Dynamical evidence, supported supported by laboratory simulations of interstellar dust impacts in aerogel and foils, and numerical modeling of interstellar dust propagation in the heliosphere, suggests that at least some of the particles have high optical cross-section, perhaps due to an aggregate structure. However, the observations are most consistent with a variety of morphologies

Westphal, Andrew J.↗
NASA NTRS2014

3D Observation of GEMS by Electron Tomography

Amorphous silicates in chondritic porous interplanetary dust particles (CP-IDPs) coming from comets are dominated by glass with embedded metal and sulfides (GEMS). GEMS grains are submicron-sized rounded objects (typically 100-500) nm in diameter) with anaometer-sized (10-50 nm) Fe-Ni metal and sulfide grains embedded in an amorphous silicate matrix. Several formation processes for GEMS grains have been proposed so far, but these models are still being debated [2-5]. Bradley et al. proposed that GEMS grains are interstellar silicate dust that survived various metamorphism or alteration processes in the protoplanetary disk and that they are amorphiation products of crystalline silicates in the interstellar medium by sputter-deposition of cosmic ray irradiation, similar to space weathering [2,4]. This consideration is based on the observation of nano-sized crystals (approximately 10 nm) called relict grains in GEMS grains and their shapes are pseudomorphs to the host GEMS grains. On the other hand, Keller and Messenger proposed that most GEMS formed in the protoplanetary disk as condensates from high temperature gas [3,5]. This model is based on the fact that most GEMS grains have solar isotopic compositions and have extremely heterogeneous and non-solar elemental compositions. Keller and Messenger (2011) also reported that amorphous silicates in GEMS grains are surrounded by sulfide grains, which formed as sulfidization of metallic iron grains located on the GEMS surface. The previous studies were performed with 2D observation by using transmission electron microscopy (TEM) or scanning TEM (STEM). In order to understand the structure of GEMS grains described above more clearly, we observed 3D structure of GEMS grains by electron tomography using a TEM/STEM (JEM-2100F, JEOL) at Kyoto University. Electron tomography gives not only 3D structures but also gives higher spatial resolution (approximately a few nm) than that in conventional 2D image, which is restricted by sample thickness ) approx. or greater than 50 nm). Three cluster IDPs (L2036AA5 cluster4, L2009L8 cluster 13 and W726A2) were used for the observations. ID W726A2 was collected without silicon oil, which is ordinary used to collect IDPs, so this sample has no possibility of contaminations caused by silicon oil or solvent to rinse it [6]. The samples were embedded in epoxy risin and sliced into ultrathin sections (50-300 nm) using an ultramicotome. The sections were observed by BF-TEM and HAADF-STEM (high angle annular dark field-scanning TEM) modes. Images were obtained by rotating the sample tilt angle over a range of +/- 65 deg in 1 deg steps. The obtained images were reconstructed to slice images. Mineral phases in the slice images were estimated by comparing with a 2D elemental map obtained by an EDS (energy dispersive X-ray spectroscopy) system equipped in the TEM/STEM. Careful examination of the slice images confirmed that iron grains are embedded in the amorphous silicate matrix of the GEMS grains, but sulfide grains were mainly present on the surface of the amorphous silicate. These results are consistent with the model that GEMS grains formed as condensates [3,5], although more data are needed to conclude the origin of GEMS grains. The present study is the first successful example adapting the electron tomography to the IDPs. This type of analysis will be important for planetary material sciences in the future.

Matsuno, Junya↗