Organic Matter In Space Research Articles

Three-dimensional space and time mapping reveals soil organic matter decreases across anthropogenic landscapes in the Netherlands

For restoring soil health and mitigating climate change, information of soil organic matter is needed across space, depth and time. Here we developed a statistical modelling platform in three-dimensional space and time as a new paradigm for soil organic matter monitoring. Based on 869 094 soil organic matter observations from 339,231 point locations and the novel use of environmental covariates variable in three-dimensional space and time, we predicted soil organic matter and its uncertainty annually at 25 m resolution between 0–2 m depth from 1953–2022 in the Netherlands. We predicted soil organic matter decreases of more than 25% in peatlands and 0.1–0.3% in cropland mineral soils, but increases between 10–25% on reclaimed land due to land subsidence. Our analysis quantifies the substantial variations of soil organic matter in space, depth, and time, highlighting the inadequacy of evaluating soil organic matter dynamics at point scale or static mapping at a single depth for policymaking.

Formation and Evolution Mechanisms for Organic Matter in Space

Organic compounds are a major component of dust in molecular clouds, alongside silicates and water ice, due to the high abundances of elements that make up these compounds in the Galaxy. The initial molecular inventory of the Solar System, inherited from the molecular cloud, was modified and new complex molecules were formed in the protoplanetary disk and planetesimals. Because astronomical observations mainly target gas, while cosmochemical evidence deals with solid phases, it is crucial to link discrepant knowledge on organic species through state-of-the-art modeling. This chapter reviews the latest understanding of surface reactions on inter-stellar dusts, gas–dust reactions in the protoplanetary disk, and alteration processes on planetesimals in the early Solar System.

Integrative analytical workflow to enhance comprehensive analysis of organic molecules in extraterrestrial objects.

Molecular identification is a fundamental issue in astrobiology to investigate the routes of emergence of life on our planet involving in particular a potential seeding of extraterrestrial organic matter on the primitive Earth. However, this project encompasses major difficulties due to the low concentration of molecules present in bodies of the Solar System. This work proposes an integrative analytical workflow, no longer based on GC-MS instruments, to enhance comprehensive analysis of organic markers in these objects. Our strategy combines UPLC-HRMS and UPLC-MRM MS methods to bring both a broad molecular mapping and detailed data on indigenous compounds present in any extraterrestrial objects or laboratory analogs. Applied on water extracts from fresh meteorites, our workflow highlights a wide range of free molecules in the non-treated extracts and reveals the wide diversity of amino acid and nucleobase isomers that could lead to misinterpretation as far as the molecular composition of meteorite extracts cannot be anticipated. This strategy, never explored so far, would provide new clues for studying the organic matter in space and should offer new perspectives on its evolution and reactivity.

Petroleum, coal and other organics in space

The petroleum and coal models of the unidentified infrared emissions (UIE), sometimes referred also as unidentified infrared bands (UIBs) has been reviewed mainly based on the work of the authors with the inclusion of unpublished results. It is shown that the petroleum and coal model of the UIE converges and merges quite well with the MAON (Mixed Aromatic Aliphatic Organic Nanoparticles) model of the UIE. It is shown that the thermal treatment of various substrates like PAHs, alkylated PAHs but also mixed aliphatic/olefinic substrates leads invariable to carbonaceous materials matching the infrared spectrum of anthracite coal or certain petroleum fractions. Thus, the experimental thermal processing (which under space conditions could be equivalent to the expected processing by shock waves or high energy radiation) of mixed aromatic/aliphatic organic matter can be used to match also the UIE evolution. Another way to simulate the thermal/radiation processing of organic matter in space, can be achieved through the carbon arc. Simple substrates processed in this way produce carbon soot and a plethora of organic molecules. Fullerenes are found in space both through mid-infrared and optical spectroscopy and it is very likely that other complex related species such as endohedral fullerenes (i.e. fullerenes with a metal, heteroatom or molecules inside the cage) may be formed in space. After all, their formation requires the same conditions as those needed for fullerene formation provided that also a metal vapour (e.g. interstellar/circumstellar gas) is available. The last part of this review is thus dedicated to the recent results on the study and characterization of an endohedral C60 derivative containing lithium inside the cage.

宇宙の有機物(宇宙の化学)( 宇宙と化学)

宇宙の有機物(宇宙の化学)( 宇宙と化学)

Different sizes of diamond formation in natural processes

On the basis of geological and astrophysical data, it is possible to distinguish three different mechanisms of diamond formations of different sizes. The first one is the formation of macrodiamonds in the upper mantle rocks formed at high pressures and temperatures. The second one is micron-sized diamond formation in rocks of the Earth’s crust formed at P-T parameters corresponding to graphite stability. The third one is nanodiamond (less than 100 nm) formation at 300–500°C and low pressures from organic matter in space. On the basis of theoretical and experimental data, it is possible to conclude that the different sizes of diamonds could have been formed in a wide range of pressures and temperatures in natural processes and their size is connected with the P-T parameters.

Organic matter in the universe

1. History and introduction 2. The chemistry of organic matter 2.1 families of organic molecules 2.2 different forms of carbon 2.3 chains and rings 2.4 molecules of biological significance 3. Techniques of detecting organic molecules in space 3.1 Electronic structure of molecules 3.2 Rotational transitions 3.3 Vibrational transitions 3.4 Electronic transitions 3.5 Nuclear spin and hyperfine lines 3.6 Radical and molecular ions 3.7 Ground-based observations and spectroscopic observations from space 4. Organic molecules in the diffuse interstellar medium 5. Organic compounds in galaxies 6. Synthesis of organic compounds in the late stages of stellar evolution 6.1 nucleosynthesis of carbon 6.2 stellar winds and the late stages of stellar evolution 6.3 synthesis of gas-phase molecules and the condensation of solids 6.4 physical conditions of the stellar wind and chemical pathways of synthesis 6.5 emergence of aliphatic and aromatic compounds and their ejection into the interstellar medium 7. Organic compounds in the Solar System 7.1 meteorites 7.2 interplanetary dust particles 7.3 comets 7.4 asteroids 7.5 planetary satellites 8. Organic compounds as carriers of unsolved astronomical phenomena 8.1 unidentified infrared emission features 8.2 diffuse interstellar bands 8.3 the 217 nm feature 8.4 extended red emission 8.5 the 21 and 30 micron emission features 9. Chemical structures of organic matter in space 9.1 polycyclic aromatic hydrocarbons 9.2 hydrogenated amorphous carbon and carbon nanoparticles 9.3 quenched carbonaceous composites 9.4 kerogen and coal 9.5 tholin and HCN polymers 10. Laboratory simulations of molecular synthesis 10.1 Miller-Urey experiment 10.2 Ultraviolet photolysis of ices 11. Delivery of organic compounds in the early history of the Earth 11.1 isotopic signatures and the existence of presolar grains 11.2 crater records and the heavy bombardment phase in the early history of the Earth 12. Origin of life on Earth 12.1 endogenous and exogenous theories of origin of life 12.2 organic compounds and the first emergence of life 13. Outlook for the future 13.1 future astronomical facilities 13.2 future Solar System exploration missions 14. References 15. Glossary 16. Subject index 17. Object index

The evolution of organic matter in space

Carbon, and molecules made from it, have already been observed in the early Universe. During cosmic time, many galaxies undergo intense periods of star formation, during which heavy elements like carbon, oxygen, nitrogen, silicon and iron are produced. Also, many complex molecules, from carbon monoxide to polycyclic aromatic hydrocarbons, are detected in these systems, like they are for our own Galaxy. Interstellar molecular clouds and circumstellar envelopes are factories of complex molecular synthesis. A surprisingly high number of molecules that are used in contemporary biochemistry on the Earth are found in the interstellar medium, planetary atmospheres and surfaces, comets, asteroids and meteorites and interplanetary dust particles. Large quantities of extra-terrestrial material were delivered via comets and asteroids to young planetary surfaces during the heavy bombardment phase. Monitoring the formation and evolution of organic matter in space is crucial in order to determine the prebiotic reservoirs available to the early Earth. It is equally important to reveal abiotic routes to prebiotic molecules in the Earth environments. Materials from both carbon sources (extra-terrestrial and endogenous) may have contributed to biochemical pathways on the Earth leading to life's origin. The research avenues discussed also guide us to extend our knowledge to other habitable worlds.

Heavy negative ions in Titan's ionosphere: Altitude and latitude dependence

One of the unexpected results of the Cassini mission was the discovery of negative ions at altitudes between 950 and 1400 km in Titan's ionosphere with masses up to 10,000 amu/q [Coates, A.J., Crary, F.J., Lewis, G.R., Young, D.T., Waite Jr., J.H., Sittler Jr., E.C., 2007. Discovery of heavy negative ions in Titan's ionosphere. Geophys. Res. Lett., 34, L22103, doi:10.1029/2007GL030978; Waite Jr., J.H., Young, D. T., Coates, A. J., Crary, F. J., Magee, B. A., Mandt, K. E., Westlake, J. H., 2008. The Source of Heavy Organics and Aerosols in Titan's Atmosphere, submitted to Organic Matter in Space, Proceedings IAU Symposium no. 251]. These ions are detected at low altitudes during Cassini's closest Titan encounters by the Cassini plasma spectrometer (CAPS) electron spectrometer. This result is important as it is indicative of complex hydrocarbon and nitrile chemical processes at work in Titan's high atmosphere. They may play a role in haze formation and ultimately in the formation of heavy particles (tholins), which fall through Titan's atmosphere and build up on the surface. During Cassini's prime mission negative ions were observed on 23 Titan encounters, including 7 in addition to those reported by Coates et al. [Coates, A.J., Crary, F.J., Lewis, G.R., Young, D.T., Waite Jr., J.H., Sittler Jr., E.C., 2007. Discovery of heavy negative ions in Titan's ionosphere. Geophys. Res. Lett., 34, L22103, doi:10.1029/2007GL030978]. Here, we also examine the altitude and latitude dependence of the high-mass negative ions observed in Titan's ionosphere, and we examine the implications of these results. We find that the maximum negative ion mass is higher at low altitude and at high latitudes. We also find a weaker dependence of the maximum mass on solar zenith angle.

Organic matter in space: from star dust to the Solar System

Organic compounds of high degree of complexity are now known to be widespread in the Universe, ranging from objects in our Solar System to distant galaxies. Through the techniques of millimeter-wave spectroscopy, over 140 molecules have been identified through their rotational transitions. Space infrared spectroscopy has detected the stretching and bending modes of compounds with aromatic and aliphatic structures. Analyses of samples of meteorites, comets, asteroids, and interplanetary dust also revealed a rich content of organic substances, some of which could be of extra-solar origin. We review the current state of understanding of the origin, evolution, nature, and distribution of organic matter in space. Also discussed are a number of unexplained astronomical phenomena whose origins could be traced to organic carriers.

A tracer of organic matter of prebiotic interest in space, made from UV and thermal processing of ice mantles

Aims. Our main goal was to identify an infrared spectral feature that can serve as a tracer of O and N-rich solid organic matter in space. Such material is expected to result from UV-irradiation and sublimation of icy grain mantles in certain environments, including hot cores and regions around YSOs. Our analysis of the 3.4 μm feature, present in the spectra of organic refractory samples made from UV-irradiation of interstellar/circumstellar ice analogs, indicates that the 3.4 pm band is a potential tracer of O and N-rich solid organic matter of prebiotic interest in space. Methods. We carried out simulation experiments of UV-photoprocessing and sublimation of ice mantles in dense clouds and circumstellar regions leading to the formation of organic refractory residues under different conditions. The analysis of the deposited ice and the organic residue products was made in situ by infrared spectroscopy. Spectral comparison of these residues to molecular standards for compositional characterization was performed. Results. For ice mixtures of different composition, UV-photon dose and frequency, the 3.4 μm feature of the organic residue product at room temperature shows a broad double-peaked profile with subfeatures at ∼2926 cm -1 (3.42 μm) and 2876 cm -1 (3.48 pm), mainly due to CH 2 groups adjacent to OH groups. This feature profile was not reproduced in similar UV-irradiation experiments using non-realistic analogs of interstellar ice mantles. In the astrophysical context, this infrared feature is thus expected to be characteristic of the products resulting from ice UV-irradiation and sublimation; it is fully distinct from the 3.4 μm feature observed in the diffuse interstellar medium, which is attributed to hydrogenated amorphous carbon. Conclusions. A 3.4 μm band with a similar broad double-peaked profile tracing organic refractory matter of prebiotic interest could be searched for in regions where icy grain mantles were exposed to UV-irradiation prior to sublimation, like hot cores and regions around YSOs. This band may also be present in some cometary nuclei that preserve such grains, provided that the annealing temperatures experienced were not higher than ∼400 K.

PAHs in Astronomy - A Review

AbstractCarbonaceous materials play an important role in space. Polycyclic Aromatic Hydrocarbons (PAHs) are a ubiquitous component of organic matter in space. Their contribution is invoked in a broad spectrum of astronomical observations that range from the ultraviolet to the far-infrared and cover a wide variety of objects and environments from meteorites and interplanetary dust particles to outer Solar System bodies to the interstellar medium in the local Milky Way and in other galaxies. Extensive efforts have been devoted in the past two decades to experimental, theoretical, and observational studies of PAHs. A brief review is given here of the evidence obtained so far for the contribution of PAHs to the phenomena aforementioned. An attempt is made to distinguish the cases where solid evidence is available from cases where reasonable assumptions can be made to the cases where the presence - or the absence - of PAHs is purely speculative at this point.

IAU Symposium 251: Organic Matter in Space, Hong Kong, China, 18-22 February 2008

IAU Symposium 251: Organic Matter in Space, Hong Kong, China, 18-22 February 2008

Complex organic matter in space: about the chemical composition of carriers of the Unidentified Infrared Bands (UIBs) and protoplanetary emission spectra recorded from certain astrophysical objects.

In this communication we present the basic concept that the pure PAHs (Polycyclic Aromatic Hydrocarbons) can be considered only the ideal carriers of the UIBs (Unidentified Infrared Bands), the emission spectra coming from a large variety of astronomical objects. Instead we have proposed that the carriers of UIBs and of protoplanetary nebulae (PPNe) emission spectra are much more complex molecular mixtures possessing also complex chemical structures comparable to certain petroleum fractions obtained from the petroleum refining processes. The demonstration of our proposal is based on the comparison between the emission spectra recorded from the protoplanetary nebulae (PPNe) IRAS 22272+ 5435 and the infrared absorption spectra of certain 'heavy' petroleum fractions. It is shown that the best match with the reference spectrum is achieved by highly aromatic petroleum fractions. It is shown that the selected petroleum fractions used in the present study are able to match the band pattern of anthracite coal. Coal has been proposed previously as a model for the PPNe and UIBs but presents some drawbacks which could be overcome by adopting the petroleum fractions as model for PPNe and UIBs in place of coal. A brief discussion on the formation of the petroleum-like fractions in PPNe objects is included.

Energy density effects in the formation of organic residues in frozen methane by MeV ions

Carbonaceous residues were formed by irradiation of thin layers of frozen methane at 10 to 15 K by 17 MeV protons and 3He2+ ions and successive warming to ambient temperature. Analysis was performed by optical microscopy, scanning electron microscopy (SEM), Rutherford backscattering spectroscopy (RBS), elastic recoil detection analysis (ERDA), infrared spectroscopy (IR) in transmission, hydrogen nuclear magnetic resonance (1H-NMR), high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). Long chain aliphatic and olefinic hydrocarbons constituted the main products. The formation of aromatic and polycyclic compounds, PAHs and amorphous carbon increased with the energy deposited in one collision cascade.The linear energy transfer with respect to CH4, LT(CH4), was varied in the systems p//Ar/CH4 (12:1), p//CH4 and 3He2+//CH4 from 160 to 10810 eVμm−1, respectively. A threshold LT for the formation of PAHs and related structures seems to range between 2 and 10 keVμm−1. The experiments give evidence for a fast multicenter combination of intermediate radicals formed by the secondary suprathermal carbon atoms from knock on processes in one collision cascade. The experiments were aimed to simulate the effects of cosmic rays on primordial frozen matter. The results underline the role of heavier ion irradiation (He, etc.) in the prebiotic buildup of complex organic matter in space.