Search

We explored the photocatalytic (UV-driven) reduction of CO2 on mineral surfaces in acidic conditions and observed the production of methane. Based on our measured laboratory reaction rates, we esti...

Several of the Venera, Vega and Pioneer probe data as well as ground based observation support the presence of so-called Redox Disequilibrium Pairs (RDPs) in atmosphere of so hostile world as Venus (Greaves 2021). State of the art chemical networks cannot explain origin of an important RDP, phosphine, in oxidized atmosphere of Venus by a conventional processes (Bains 2021). We used the hybrid Density Functional Theory (DFT) for investigation of a series of chemical reaction pathways leading to the reduction of phosphate monoxide to phosphine. Our calculations indicated that a reaction network similar to photochemical synthesis of methane from carbon monoxide over acidic surfaces suggested for Mars (Civiš 2019) can also occur in clouds of Venus. As a seminal step, we have explored – via state-of-the-art quantum-based calculations – the a priori energetic feasibility of the following reaction:HCO(radical) + PO = CO2 + PH (biradical).Our calculations have shown that chemical conversion is constituted of three steps. Two of them are energetically favoured, however, the final conversion to phosphine is hardened by a significant activation barrier. This barrier can be overcome by a reaction of OPH radical with hydrogen radical. For assessing the potential of the newly introduced reaction mechanisms, models of the Venus and early Earth atmospheres in ARGO code and modified STAND chemical network were created and verified. Comparison of reaction yields suggests that this pathway is potentially effective enough and could be the source of phosphine recently discovered on Venus. We acknowledge the support provided by the Czech Science Foundation within the project reg. no. 21-11366S and by ERDF/ESF "Centre of Advanced Applied Sciences" (No. CZ.02.1.01/0.0/0.0/16_019/0000778). We acknowledge support of the Czech Academy of Sciences, Strategy AV21, project VP16. The Czech team is part of the VenSpec-H Consortium onboard the ESA EnVision mission.References:Civiš S. et al.: Formation of Methane and (Per)Chlorates on Mars. ACS Earth Space Chem. 2019, 3, 2, 221–232.Bains W. et al.: Phosphine on Venus Cannot Be Explained by Conventional Processes. Astrobiology 2021, 10 (21), 1277-1304.Greaves J. S. et al.: Phosphine gas in the cloud decks of Venus. Nature Astronomy 2021, 5, 655–664.

Asteroids and comets are often rich in polyaromatic hydrocarbons (PAHs), which represent in general about 30 % of total carbon in space. The fate of these molecules in extraterrestrial delivery was investigated by experimentally simulating asteroid impacts – using laser induced breakdown (LIBD) – into rocky planetary atmospheres and surfaces. Experiments were performed with benzene, naphtalene and anthracene as simple members of PAHs. The effect of LIBD on chemistry of these compounds in various chemical environments, such as atmospheric composition and solid phase matrices, were also studied. The main gas phase products are acetylene and HCN, followed by CO and CO2, whose yields mainly depend on the content of water vapour in the atmosphere. A brownish solid product was also observed. Therefore, simple aromatic compounds, and likely also PAHs, can be a viable source of HCN – molecule with significant prebiotic importance– in planetary environments.

Spectra of meteor plasma, their dynamics and dominant spectral features are usually a subject of mathematical modelling and computations. In our study, on the other hand, we describe and evaluate the advantages and limitations of the experimental techniques employed for meteor spectra simulations. The experiments are performed by ablating meteorite samples using a series of laser sources, i.e. a large terawatt−class gas laser infrastructure PALS, a high-power Ti:Sapphire femtosecond laser, and laboratory Nd:YAG and ArF excimer lasers. We demonstrate that, notwithstanding the importance of theoretical spectra computation, laboratory experiments may remarkably enhance the qualitative and quantitative evaluation of the meteor emission spectra measured, as well as the assignment of important spectral features therein. We also perform completing experiments to compare the laser-target interaction observed with the expected dynamics of evaporation and disintegration of a real meteoroid body.

Is there life beyond Earth? An ideal research program would first ascertain how life on Earth began and then use this as a blueprint for its existence elsewhere. But the origin of life on Earth is still not understood, what then could be the way forward? Upcoming observations of terrestrial exoplanets provide a unique opportunity for answering this fundamental question through the study of other planetary systems. If we are able to see how physical and chemical environments similar to the early Earth evolve we open a window into our own Hadean eon, despite all information from this time being long lost from our planet’s geological record. A careful investigation of the chemistry expected on young exoplanets is therefore necessary, and the preparation of reference materials for spectroscopic observations is of paramount importance. In particular, the deduction of chemical markers identifying specific processes and features in exoplanetary environments, ideally “uniquely”. For instance, prebiotic feedstock molecules, in the form of aerosols and vapours, could be observed in transmission spectra in the near future whilst their surface deposits could be observed from reflectance spectra. The same detection methods also promise to identify particular intermediates of chemical and physical processes known to be prebiotically plausible. Is Ariel truly able to open a window to the past and answer questions concerning the origin of life on our planet and the universe? In this paper, we discuss aspects of prebiotic chemistry that will help in formulating future observational and data interpretation strategies for the Ariel mission. This paper is intended to open a discussion and motivate future detailed laboratory studies of prebiotic processes on young exoplanets and their chemical signatures.

The photocatalytic reduction of CO2 to CH4 is a chemical process that to some extent occurs on a planetary surface of terrestrial planets. The effect of acidic proton on the rate of the photocataly...

Quantum dots (QDs) are usually seen as artificial semiconductor particles exhibiting optical and electronic properties interesting for nanotechnological applications. However, they may also play a role in prebiotic chemistry. Starting from zinc acetate, cadmium acetate, and mercaptosuccinic acid, we demonstrate the formation of ZnCd QDs upon UV irradiation in prebiotic liquid formamide. We show that ZnCd QDs are able to increase the yield of RNA nucleobase synthesis from formamide up to 300 times, suggesting they might have served as universal catalysts in a primordial milieu. Based on the experimentally observed peroxidase-like activity of ZnCd QDs upon irradiation with visible light, we propose that QDs could be relevant to a broad variety of processes relating to the emergence of terrestrial life.

Ariel, the Atmospheric Remote-sensing Infrared Exoplanet Large-survey, was adopted as the fourth medium-class mission in ESA's Cosmic Vision programme to be launched in 2029. During its 4-year mission, Ariel will study what exoplanets are made of, how they formed and how they evolve, by surveying a diverse sample of about 1000 extrasolar planets, simultaneously in visible and infrared wavelengths. It is the first mission dedicated to measuring the chemical composition and thermal structures of hundreds of transiting exoplanets, enabling planetary science far beyond the boundaries of the Solar System. The payload consists of an off-axis Cassegrain telescope (primary mirror 1100 mm x 730 mm ellipse) and two separate instruments (FGS and AIRS) covering simultaneously 0.5-7.8 micron spectral range. The satellite is best placed into an L2 orbit to maximise the thermal stability and the field of regard. The payload module is passively cooled via a series of V-Groove radiators; the detectors for the AIRS are the only items that require active cooling via an active Ne JT cooler. The Ariel payload is developed by a consortium of more than 50 institutes from 16 ESA countries, which include the UK, France, Italy, Belgium, Poland, Spain, Austria, Denmark, Ireland, Portugal, Czech Republic, Hungary, the Netherlands, Sweden, Norway, Estonia, and a NASA contribution., Comment: Ariel Definition Study Report, 147 pages. Reviewed by ESA Science Advisory Structure in November 2020. Original document available at: https://www.cosmos.esa.int/documents/1783156/3267291/Ariel_RedBook_Nov2020.pdf/

Two sets of NH3 absorption spectra covering the 0.793 μm region are recorded using two Bruker IFS 125 HR Fourier transform spectrometers. Three unapodized absorption spectra are recorded in Brussels over the range 11000−14500 cm−1 and the positions and intensities of 1114 ammonia lines observed in the 12491−12810 cm−1 region are measured using a multi-spectrum least squares fitting algorithm. 367 additional lines are identified in an ammonia absorption spectrum recorded in two steps at the J. Heyrovsky Institute of Physical Chemistry in Prague, using two different interference filters covering the 12000−12500 and 12400−13000 cm−1 ranges. The 1481 measured ammonia lines are analyzed using an empirical line list computed using variational nuclear motion calculations and ground state combination differences. Transitions are assigned to vibrational states with 4νNH stretching excitation (v1+v3=4). 278 out of the 1481 measured lines are assigned to 300 transitions and 119 upper state energy levels are derived from the frequencies of the assigned transitions., SCOPUS: ar.j, info:eu-repo/semantics/published

In a combined experimental and theoretical study, we probe the vibrational excitation of isocyanic acid induced by electron impact in the energy range up to 5 eV. Experimentally, we report differential elastic and vibrationally inelastic cross sections at the scattering angle of ${135}^{\ensuremath{\circ}}$. Theoretically, we characterize the involved resonant states using a regularized analytical continuation method. We also apply a nonlocal resonance model to calculate cross sections for vibrational mode that involves the N-H stretching motion. The model reproduces all the features observed in the experiment: efficient excitation at threshold, sharp cusps in the excitation functions, and the formation of an ${A}^{\ensuremath{'}}$ shape resonance. There is a second $({A}^{\ensuremath{'}\ensuremath{'}})$ resonance visible in the spectra; however, it excites only selected vibrational modes. The origins of this selectivity are discussed.

Besides delivering plausible prebiotic feedstock molecules and high-energy initiators, extraterrestrial impacts could also affect the process of abiogenesis by altering the early Earth's geological environment in which primitive life was conceived. We show that iron-rich smectites formed by reprocessing of basalts due to the residual post-impact heat could catalyze the synthesis and accumulation of important prebiotic building blocks such as nucleobases, amino acids and urea.

Multilayer graphene and mica cantilevers as part of an optical microphone in combination with CO2 laser emitting in the range of 9–11 μm were employed in a multicomponent analysis of a mixture of acetone, acetic acid and methanol by photoacoustic spectroscopy. Using these elements, the detection limits of mica circle cantilever were 0.54, 0.80 and 24.8 ppm for acetic acid, methanol and acetone, respectively; these limits were approximately 5 times lower than the detection limit of the highest-class microphone used in this study. The multicomponent analysis was performed using five selected CO2 laser lines and a classical method of least squares. Despite the inaccuracies of our system, very good agreement between the concentration of acetic acid calculated from the photoacoustic signal and from weighing of concentration standards (~3%) was found when measuring the signal in a 10:1:1 mixture of acetone:acetic acid:methanol at five selected laser lines. The absorption coefficient of acetic acid at 10.24 μm was almost 500 times higher than that of acetone, which showed the good ability of this method to detect acetic acid in a high background of acetone, which can be beneficial in the medical analysis of breath.

Methane, perchlorates, chlorates, and methyl chlorides have all been detected on Mars. The origin of these species has never been adequately explained. In this paper, we irradiated mixtures of CO2,...

The era of fossil fuels is slowly nearing its inevitable end and the urgency of alternative energy sources basic research, exploration and testing becomes ever more important. Storage and alternative production of energy from fuels, such as methane, represents one of the many alternative approaches. Natural gas containing methane represents a powerful source of energy producing large volume of greenhouse gases. However, methane can be also produced in closed, CO2-neutral cycles. In our study, we compare detailed chemical composition of CH4 fuel produced in two different processes: Classical production of biogas in a rendering station, industrial wastewater treatment station and landfill gas station together with novel approach of artificial photosynthesis from CO2 over acidic anatase TiO2 in experimental apparatus developed in our laboratory. The analysis of CH4 fuel produced in these processes is important. Trace gaseous traces can be for example corrosive or toxic, low quality of the mixture suppresses effectivity of energy production, etc. In this analysis, we present a combination of two methods: High resolution Fourier transform infrared spectroscopy (HR-FTIR) suitable for the main component analysis; and the complementary extremely sensitive method of Selected Ion Flow Tube Mass Spectrometry (SIFT-MS) and gas chromatography (GC–MS), which are in turn best suited for trace analysis. The combination of these methods provides more information than any single of them would be able to and promises a new possible analytical approach to fuel and gaseous mixture analysis.

Understanding the chemical evolution of newly formed terrestrial planets involves uncertainties in atmospheric chemical composition and assessing the plausibility of biomolecule synthesis. In this study, an original scenario for the origin of methane on Mars and terrestrial planets is suggested. Carbon dioxide in Martian and other planetary atmospheres can be abiotically converted into a mixture of methane and carbon monoxide by ‘methanogenesis’ on porous mineral photoactive surfaces under soft ultraviolet irradiation. On young planets exposed to heavy bombardment by interplanetary matter, this process can be followed by biomolecule synthesis through the reprocessing of reactive reducing atmospheres by impact-induced shock waves. The proposed mechanism of methanogenesis may help to answer the question concerning the formation of methane and carbon monoxide by photochemical processes, the formation of biomolecules on early Earth and other terrestrial planets, and the source and seasonal variation of methane concentrations on Mars. Experiments are presented that indicate that methane can be produced abiotically on Mars through the photocatalytic reaction of CO2, in a process called methanogenesis. Methane can then be shocked (through impacts) to form RNA nucleobases and glycine.

Recent results in prebiotic chemistry implicate hydrogen cyanide (HCN) as the source of carbon and nitrogen for the synthesis of nucleotide, amino acid and lipid building blocks. HCN can be produced during impact events by reprocessing of carbonaceous and nitrogenous materials from both the impactor and the atmosphere; it can also be produced from these materials by electrical discharge. Here we investigate the effect of high energy events on a range of starting mixtures representative of various atmosphere-impactor volatile combinations. Using continuously scanning time–resolved spectrometry, we have detected ·CN radical and excited CO as the initially most abundant products. Cyano radicals and excited carbon monoxide molecules in particular are reactive, energy-rich species, but are resilient owing to favourable Franck–Condon factors. The subsequent reactions of these first formed excited species lead to the production of ground-state prebiotic building blocks, principally HCN.

Terrestrial volcanism has been one of the dominant geological forces shaping our planet since its earliest existence. Its associated phenomena, like atmospheric lightning and hydrothermal activity, provide a rich energy reservoir for chemical syntheses. Based on our laboratory simulations, we propose that on the early Earth volcanic activity inevitably led to a remarkable production of formic acid through various independent reaction channels. Large-scale availability of atmospheric formic acid supports the idea of the high-temperature accumulation of formamide in this primordial environment.

The chemical environments of young planets are assumed to be largely influenced by impacts of bodies lingering on unstable trajectories after the dissolution of the protoplanetary disk. We explore the chemical consequences of impacts within the context of reducing planetary atmospheres dominated by carbon monoxide, methane and molecular nitrogen. A terawatt high-power laser was selected in order to simulate the airglow plasma and blast wave surrounding the impactor. The chemical results of these experiments are then applied to a theoretical atmospheric model. The impact simulation results in substantial volume mixing ratios within the reactor of 5% hydrogen cyanide (HCN), 8% acetylene (C$_2$H$_2$), 5% cyanoacetylene (HC$_3$N) and 1% ammonia (NH$_3$). These yields are combined with estimated impact rates for the Early Earth to predict surface boundary conditions for an atmospheric model. We show that impacts might have served as sources of energy that would have led to steady-state surface quantities of 0.4% C$_2$H$_2$, 400 ppm HCN and 40 ppm NH$_3$. We provide simulated transit spectra for an Earth-like exoplanet with this reducing atmosphere during and shortly after eras of intense impacts. We predict that acetylene is as observable as other molecular features on exoplanets with reducing atmospheres that have recently gone through their own `Heavy Bombardments', with prominent features at 3.05 $\mu$m and 10.5 $\mu$m., Comment: 26 pages, 12 figures, 2 tables, accepted for publication by The Astrophysical Journal

The intensity ratio of the D 1 and D 2 sodium-doublet emission lines varies both across spectra of astronomical sources and in laboratory plasmala. This article probes the behaviour of this ratio under controlled laboratory conditions. In order to study this variation, we have recorded microwave discharge spectra of sodium vapour in range of 15000 to 18000 cm − 1 . Emission bands of the molecular nitrogen buffer gas and kinetic broadening of nitrogen and sodium lines have been used in a characterisation of the discharge temperature. We show that the relative intensity of doublet lines is determined by self-absorption and depends on the buffer-gas pressure and discharge power. The ratio and line shapes can be explained by a two-temperature model of sodium emission and foreground absorption. Line ratios estimated for spectra with various strength of the self-absorption of electric discharges can be used for characterising their temperatures and densities. In contemporary astronomical observation of exoplanetary atmospheres, this effect has not been resolved yet. To observe this effect, at least 0.01 - 0.05 cm − 1 resolution (resolving power 1 600 000) is required. We make a connection to stellar Na emission and possible absorption processes for future observations of exoplanetary atmospheres.

In a series of our previously published papers, we reported a broad range of experiments and theoretical studies devoted to the interaction of carbon dioxide with the anatase titania surface. In the current study, we demonstrate oxygen mobility between gaseous carbon dioxide and solid natural clay minerals. This surprising feature implies that such behaviour is typical not only for titania but also for oxides with different chemical composition and structure. The oxygen mobility was demonstrated by the interaction of isotopically labelled carbon dioxide – C 18 O 2 – with the mineral surfaces. In most cases, we observed rapid oxygen exchange between the gas and the mineral. It was therefore discovered that carbon dioxide is more active than was previously thought because it exchanges its oxygen atoms with inorganic surfaces. Moreover, this feature seems to be very significant in natural clays of various compositions. This finding points not only towards high activity of CO 2 but also towards high surface reactivity of clays, which are quite common surface minerals on Earth and other planets.

Recently, many studies have demonstrated that carbon dioxide can be converted to methane on TiO 2 surface by a photocatalytic process. We show that such a photo-reduction can be significantly affected by the presence of an acidic proton in powder samples of titania. Using in situ absorption gas-phase rovibrational spectroscopic detection of CH 4 , CO and CO 2 , we demonstrate that proton enhancement positively affects transformation of intermediate derivatives to methane during the photo-irradiation process via several reactions in which the electron transfer inside titania is coupled to oxygen transfer to the Ti 3+ centers of TiO 2 structure. The yield of CH 4 or CO depends on the surface conditioning of titania: the formation of CH 4 is boosted by a presence of adsorbed HCl, while the formation of CO is boosted by adsorbed H 2 SO 4 .

The main objective of this study is to provide data on the bulk elemental composition, mineralogy and the possible origin of the Porangaba meteorite, whose fall was observed at 17:35 UT on 9 January 2015 on several sites of the state of Sao Paulo in Brazil. The surface of the meteorite was mapped by Scanning Electron Microscopy (SEM) and optical microscopy. The mineralogy and the bulk elemental composition of the meteorite were studied using Energy-Dispersive and Wavelength-Dispersive X-ray Spectroscopy (EDS/WDS) together with Electron Back Scatter Diffraction (EBSD). The bulk elemental composition was also independently analysed by Atomic Absorption Spectrometry (AAS), Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Laser Ablation ICP MS (LA ICP-MS) and Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS). Based on the available visual camera records of the Porangaba meteorite fall, its orbit was tentatively calculated, and possible candidates for the source bodies in the Solar system were proposed. We also present a laboratory simulation of a Porangaba-like (L4 Ordinary Chondrite) meteor emission spectra. These can be used as benchmark spectra for the identification of meteor rock types through their comparison with meteor spectra recorded by high-speed video-cameras equipped with simple grating spectrographs.

One of the exceptional features of CO2 is its ability to interact with solid surfaces on a common basis. This interaction takes the form of an adsorption and can be monitored by isotope labelling. Oxygen isotope-labelled CO2 added to a mineral, most importantly TiO2, exchanges its oxygen atoms with the sample and the changing isotopic composition can be monitored by high-resolution Fourier transform infrared spectroscopy.

Last a few decades have witnessed a rising scientific interest in two well-known molecules—carbon dioxide and titania. The fundamental properties such as their chemistry, structure and application potential are well known. However, the main problem concerning CO2—the global change of climate—has not been dealt with yet. The ever-rising levels of carbon dioxide in the atmosphere, utilization of fossil fuels and the effects on global climate portend the need for a cleaner energy supply as well as the need to reduce the CO2 amount present in the atmosphere of our planet. Importantly, several recent discoveries have pointed out that novel materials based on TiO2 are able to solve climate change by establishing a new methane cycle-based energetics and economy.

The field of the origin of life research is a relatively new but rapidly growing area of research. It is not the purpose of this book to review all scientific progress in this branch. Indeed, such book would have to be quite thicker, not to mention expensive. However, several ideas that have recently come up concerning the early Earth and life’s origins include CO2 and/or TiO2 as the main protagonists. We wish to mention to a certain extent these ideas and show that photochemistry might have played a vital role in the process by which we came to being.

This chapter gives an overview of the state-of-the-art research progress in the topic of photocatalytic reduction of CO2 in selected areas of application. The knowledge of the practical uses of the photocatalytic reduction process may be beneficial to give the book more context and to specify its place in the plethora of work that is available to any reader.

The photocatalytic reduction of carbon dioxide is a process that has received significant attention in the literature of the second half of the twentieth century. This chapter shows how chemical conditions and the environment can envisage various aspects of this process and explains what consequences these findings may have on the origin of methane on terrestrial planets, which is shown on the case of Mars.

Spontaneous isotopic exchange of oxygen atoms between dry powdered Ti16O 2 oxygen containing minerals and gaseous C18O 2 was studied using gas phase high-resolution Fourier transform infrared absorption spectroscopy of carbon dioxide isotopologues. The absorption rovibrational spectra of all the measured carbon dioxide isotopologues were assigned and used for the quantification of the time-dependent isotope exchange between oxygen atoms (16O) from the crystalline lattice of the solid mineral samples and (18O) oxygen atoms from gaseous C18O 2 . Similarly to our previous studies devoted to isotopic exchange activity of titanium dioxide, we found out that rutile, montmorillonite, siderite, calcite or basaltic minerals also exhibit unexpectedly significant oxygen mobility between solid and gas phases. The rate of formation of gaseous C16O 2 is found to be highly dependent on the nature of the mineral sample. Our previous studies together with the results here presented suggest that such crystal lattice oxygen isotopes mobility can be explained by two mechanisms: cluster-like structure of finely powdered materials or the existence of oxygen deficiency sites in the structure of the crystal lattice.

The Miller–Urey experiments pioneered modern research on the molecular origins of life, but their actual relevance in this field was later questioned because the gas mixture used in their research is considered too reducing with respect to the most accepted hypotheses for the conditions on primordial Earth. In particular, the production of only amino acids has been taken as evidence of the limited relevance of the results. Here, we report an experimental work, combined with state-of-the-art computational methods, in which both electric discharge and laser-driven plasma impact simulations were carried out in a reducing atmosphere containing NH3 + CO. We show that RNA nucleobases are synthesized in these experiments, strongly supporting the possibility of the emergence of biologically relevant molecules in a reducing atmosphere. The reconstructed synthetic pathways indicate that small radicals and formamide play a crucial role, in agreement with a number of recent experimental and theoretical results.

Context. Meteor spectra are commonly interpreted using data from databases and tables. Several studies have demonstrated very sophisticated calculations of elemental compositions of meteoroid bodies based on the computation of synthetic meteor spectra or on the spectral analysis of airglow plasma containing evaporated, atomized, and ionized meteoroid matter. However, considering accuracy, reliability of computations, lack of laboratory experimental data in this field, as well as the complicated physical structure of meteor plasma, such qualitative assignment or quantitative calculations are still extensively discussed in the scientific community. Even on the laboratory level, many studies have shown the high complexity of the acquisition and interpretation of the data that are recorded with techniques of emission spectroscopy that are in fashion and philosophy similar to the spectral analysis of meteor plasma, that is, detection and quantification of the elements that are ablated from complicated multicomponent matrices. Aims. The current study is focused on the application of terawatt-class laser-induced breakdown spectroscopy (TC-LIBS) of real samples of chondritic meteorites. We recorded emission spectra with high resolution and high precision that contain spectral lines that are typical for real meteoric spectra. Experimental data were compiled in a form that is convenient for the meteoric spectra interpretation and calibration. Methods. TC-LIBS was carried out by a high-power terawatt-class laser facility, the Prague Asterix Laser System (PALS). The spectra were simultaneously recorded by an echelle high-resolution spectrograph in the UV/VIS spectral ranges and by a low-resolution spectrograph that was used for real observation of meteor spectra. We also present calculated synthetic spectra based on data from the NIST atomic spectra database. Results. We assembled etalon qualitative tables of major meteoric spectral features that can be used both for the spectral wavelength calibration of low-resolution observational instruments and for the exact interpretation of meteor spectra. The data are compared with real meteor spectra.

Large-scale plasma was created in gas mixtures containing methane using high-power laser-induced dielectric breakdown (LIDB). The composition of the mixtures corresponded to a cometary and/or meteoritic impact into the early atmosphere of either Titan or Earth. A multiple-centimeter-sized fireball was created by focusing a single 100 J, 450 ps near-infrared laser pulse into the center of a 15 L gas cell. The excited reaction intermediates formed during the various stages of the LIDB plasma chemical evolution were investigated using optical emission spectroscopy (OES) with temporal resolution. The chemical consequences of laser-produced plasma generation in a CH4–N2–H2O mixture were investigated using high resolution Fourier-transform infrared absorption spectroscopy (FTIR) and gas selected ion flow tube spectrometry (SIFT). Several simple inorganic and organic compounds were identified in the reaction mixture exposed to ten laser sparks. Deuterated water (D2O) in a gas mixture was used to separate several of the produced isotopomers of acetylene, which were then quantified using the FTIR technique.

Recent synthetic efforts aimed at reconstructing the beginning of life on our planet point at the plausibility of scenarios fueled by extraterrestrial energy sources. In the current work we show that beyond nucleobases the sugar components of the first informational polymers can be synthesized in this way. We demonstrate that a laser-induced high-energy chemistry combined with TiO2 catalysis readily produces a mixture of pentoses, among them ribose, arabinose and xylose. This chemistry might be highly relevant to the Late Heavy Bombardment period of Earth's history about 4-3.85 billion years ago. In addition, we present an in-depth theoretical analysis of the most challenging step of the reaction pathway, i.e., the TiO2-catalyzed dimerization of formaldehyde leading to glycolaldehyde.

Recent synthetic efforts aimed at reconstructing the beginning of life on our planet point at the plausibility of scenarios fueled by extraterrestrial energy sources. In the current work we show that beyond nucleobases the sugar components of the first informational polymers can be synthesized in this way. We demonstrate that a laser-induced high-energy chemistry combined with TiO2 catalysis readily produces a mixture of pentoses, among them ribose, arabinose and xylose. This chemistry might be highly relevant to the Late Heavy Bombardment period of Earth’s history about 4–3.85 billion years ago. In addition, we present an in-depth theoretical analysis of the most challenging step of the reaction pathway, i.e., the TiO2-catalyzed dimerization of formaldehyde leading to glycolaldehyde.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Aims. We aim to analyse real-time Perseid and Leonid meteor spectra using a novel calibration-free (CF) method, which is usually applied in the laboratory for laser-induced breakdown spectroscopic (LIBS) chemical analysis. Methods. Reference laser ablation spectra of specimens of chondritic meteorites were measured in situ simultaneously with a high-resolution laboratory echelle spectrograph and a spectral camera for meteor observation. Laboratory data were subsequently evaluated via the CF method and compared with real meteor emission spectra. Additionally, spectral features related to airglow plasma were compared with the spectra of laser-induced breakdown and electric discharge in the air. Results. We show that this method can be applied in the evaluation of meteor spectral data observed in real time. Specifically, CF analysis can be used to determine the chemical composition of meteor plasma, which, in the case of the Perseid and Leonid meteors analysed in this study, corresponds to that of the C-group of chondrites.

The origin of life is a longstanding enigma that fascinates scientists and the general public alike. Scientific efforts have yielded a significant amount of data over the last 100 y following a fundamental cornerstone publication: Proiskhozhozhdenie Zhizny (Origin of Life) by Alexander Ivanovich Oparin (1). Currently, the formamide-based synthesis of biomolecules catalyzed or initiated by extraterrestrial minerals may have become one of the most discussed landmarks in the field of prebiotic chemistry (2). Saladino et al. (2) show that a formamide-rich extraterrestrial body could deliver a significantly large palette of biomolecules to the early Earth. The authors demonstrate that formamide irradiation by protons—used to simulate the solar wind—in the presence of selected extraterrestrial materials (samples of the main meteorite classes) can lead to the synthesis of many basic components of the primordial soup during such a period of wandering through the early solar system. Using mass spectrometry, the authors detected nucleosides, nucleic bases, amino acids, sugars, and carboxylic acids. Although the study does not identify a universal catalyst for the synthesis of all of the biomolecules, considering the RNA world hypothesis, all of the canonical nucleic bases are synthesized together with ribose, in the presence of, for example, the NWA 1465 meteorite. The synthesis of the entire major groups of biomolecules using one family of catalyst represents a significant success.

Chemical environments of young planets are assumed to be significantly influenced by impacts of bodies lingering after the dissolution of the protoplanetary disk. We explore the chemical consequences of impacts of these bodies under reducing planetary atmospheres dominated by carbon monoxide, methane, and molecular nitrogen. Impacts were simulated by using a terawatt high-power laser system. Our experimental results show that one-pot impact-plasma-initiated synthesis of all the RNA canonical nucleobases and the simplest amino acid glycine is possible in this type of atmosphere in the presence of montmorillonite. This one-pot synthesis begins with de novo formation of hydrogen cyanide (HCN) and proceeds through intermediates such as cyanoacetylene and urea.