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The field of advanced curation is important for existing astromaterials collections, which includes samples returned by space missions, and meteorites and cosmic dust samples that have been recovered from here on Earth. In order to maximize the scientific return of the samples, contamination needs to be minimized at all stages of sample collection, preliminary examination, classification, and curation. Utilizing best practice methods, a detailed acquisition and curation plan was implemented during the UK's first two expeditions to collect Antarctic meteorites from two new blue icefields, Hutchison Icefields and Outer Recovery Icefields. This article documents the design and execution of the procedures used during the project's curation and classification processes. It describes two case studies showing the processes applied to the recovered meteorites, and reviews our experiences and lessons learned for the future. [ABSTRACT FROM AUTHOR]

The interest in the production of nanoparticles (NPs) within Ar/C2H2 reactive plasmas is increasing, driven by their potential applications in functional materials or for their analogy to cosmic dust. The growth process of NPs has been thoroughly examined using a broad array of diagnostic tools. Significant among these tools are those that determine two-dimensional distributions of NP sizes and densities. The inherent complexity of these techniques has resulted in a limited number of works that integrate these measurements with a multitude of other diagnostic tools. Here, we show a multi-diagnostic exploration of the growing process of NPs in Ar/C2H2 plasmas. The combination of in-situ techniques, such as scattered light images, optical emission spectroscopy, light extinction, quadrupole mass signals, or self-bias voltage, with ex-situ scanning electron microscopy images and FTIR spectra of the deposited dust, provides a detailed picture of the growth process. The temporal evolution of plasma parameters, coupled with chemical composition measurements, provides a comprehensive description of the dust growth phases, and the FTIR measurements reveal an appreciable difference in chemical composition between the core and shell of the NPs. Furthermore, employing a method based on the terminal falling velocity of NPs in the afterglow, the intrinsic mass density of NPs is estimated. The asymmetries observed in the spatial distributions of NP size and density are qualitatively discussed in terms of neutral drag, ion drag, and electrostatic forces. [ABSTRACT FROM AUTHOR]

Methane (CH4) is one of the major components of the icy mantle of cosmic dust prevalent in cold, dense regions of interstellar media, playing an important role in the synthesis of complex organic molecules and prebiotic molecules. Solid CH4 is considered to be formed via the successive hydrogenation of C atoms accreting onto dust: C + 4H → CH4. However, most astrochemical models assume this reaction on the ice mantles of dust to be barrierless and efficient, without considering the states of adsorption. Recently, we found that C atoms exist in either the physisorbed or chemisorbed state on compact amorphous solid water, which is analogous to an interstellar ice mantle. These distinct adsorption states considerably affect the hydrogenation reactivity of the C atom. Herein, we elucidate the reactivities of physisorbed and chemisorbed C atoms with H atoms via sequential deposition and codeposition processes. The results indicate that only physisorbed C atoms can produce CH4 on ice. Combining this finding with a previous estimate for the fraction of physisorbed C atoms on ice, we determined the upper limit for the conversion of C atoms into CH4 to be 30%. [ABSTRACT FROM AUTHOR]

We investigate the formation of red misfits (RM) using a cosmological, hydrodynamical simulation from the eagle project. Similar to observations, the RM possess less dust, higher stellar metallicities, and older stellar populations compared to blue, star-forming galaxies (BA) at the same |$M_\star$|⁠. Lagrangian particle-tracking reveals that the older ages of RM have resulted from a combined effect of higher star formation efficiency (SFE), and the earlier onset and faster net depletion of their interstellar medium (ISM). For the centrals, the latter was partially due to higher efficiency of escape from ISM, driven by stronger stellar and/or active galactic nucleus feedback (depending on the mass). There was an additional contribution to this escape from gas stripping for satellite RM, as suggested by the higher group masses (⁠|$\gtrsim 0.5$| dex) and |$\mathrm{H_2}/\mathrm{H}\, {\rm{\small I}}$| ratios (⁠|$\gtrsim 0.3$| dex). Moreover, accretion of circumgalactic gas (CGM) on to the galaxy has been less efficient for the satellites. On the metallicity front, the offsets are largely due to the disparity in SFE, causing varying degrees of enrichment through the mass transfers associated with stellar winds and supernovae. We ascribe this SFE disparity to the lower specific angular momentum (j) of freshly accreted CGM for RM, which ultimately manifested in the ISM kinematics due to interactions with cooling flows. The impact on |$j_{\rm ism}$| was further intensified by poorer alignment with the flow's |$\vec{j}$|⁠ , particularly for the satellites. Our results illuminate potential origins of RM, and motivate further exploration of this peculiar class through a synergy between observations and simulations. [ABSTRACT FROM AUTHOR]

Early-generation in situ dust detectors in near-Earth space have reported the occurrence of clusters of sub-micron dust particles that seemed unrelated to human spaceflight activities. In particular, data from the impact ionization detector onboard the HEOS-2 satellite indicate that such swarms of particles occur throughout the Earth's magnetosphere up to altitudes of 60 000 km—far beyond regions typically used by spacecraft. Further account of high-altitude clusters has since been given by the GEO-deployed GORID detector, however, explanations for the latter have so far only been sought in GEO spaceflight activity. This perspective piece reviews dust cluster detections in near-Earth space, emphasizing the natural swarm creation mechanism conjectured to explain the HEOS-2 data—i.e. the electrostatic disruption of meteoroids. Highlighting this mechanism offers a novel viewpoint on more recent near-Earth dust measurements. We further show that the impact clusters observed by both HEOS-2 and GORID are correlated with increased geomagnetic activity. This consistent correlation supports the notion that both sets of observations stem from the same underlying phenomenon and aligns with the hypothesis of the electrostatic breakup origin. We conclude that the nature of these peculiar swarms remains highly uncertain, advocating for their concerted investigation by forthcoming dust science endeavours, such as the JAXA/DLR DESTINY+ mission. This article is part of the theme issue 'Dust in the Solar System and beyond'. [ABSTRACT FROM AUTHOR]

This article explores the topic of cosmic dust and its significance in understanding the universe. Cosmic dust is found throughout our solar system and beyond, and it has posed challenges for astronomers in studying celestial objects. However, advancements in science and technology have allowed researchers to use cosmic dust as a valuable source of information about the composition and evolution of distant bodies in the universe. The article discusses the different types of cosmic dust, its role in phenomena such as interstellar reddening, and its potential to provide insights into the early stages of the universe and the origin of life on Earth. It also highlights recent space missions and laboratory simulations that have contributed to our understanding of cosmic dust. The collection of articles in this special issue of Philosophical Transactions of the Royal Society A focuses on specific aspects of cosmic dust research, including the detection and analysis of meteors and meteorites, in situ detection of dust particles in interplanetary space, and laboratory simulations of icy dust grains from subsurface ocean-bearing icy moons. [Extracted from the article]

The DESTINY+(Demonstration and Experiment of Space Technology for INterplanetary voYage with Phaethon fLyby and dUst Science) Dust Analyser (DDA) is a state-of-the-art dust telescope for the in situ analysis of cosmic dust particles. As the primary scientific payload of the DESTINY+ mission, it serves the purpose of characterizing the dust environment within the Earth–Moon system, investigating interplanetary and interstellar dust populations at 1 AU from the Sun and studying the dust cloud enveloping the asteroid (3200) Phaethon. DDA features a two-axis pointing platform for increasing the accessible fraction of the sky. The instrument combines a trajectory sensor with an impact ionization time-of-flight mass spectrometer, enabling the correlation of dynamical, physical and compositional properties for individual dust grains. For each dust measurement, a set of nine signals provides the surface charge, particle size, velocity vector, as well as the atomic, molecular and isotopic composition of the dust grain. With its capabilities, DDA is a key asset in advancing our understanding of the cosmic dust populations present along the orbit of DESTINY+. In addition to providing the scientific context, we are presenting an overview of the instrument's design and functionality, showing first laboratory measurements and giving insights into the observation planning. This article is part of a theme issue 'Dust in the Solar System and beyond'. [ABSTRACT FROM AUTHOR]

Micrometeorites are estimated to represent the main part of the present flux of extraterrestrial matter found on the Earth's surface and provide valuable samples to probe the interplanetary medium. Here, we describe large and representative collections of micrometeorites currently available to the scientific community. These include Antarctic collections from surface ice and snow, as well as glacial sediments from the eroded top of nunataks—summits outcropping from the icesheet—and moraines. Collections extracted from deep-sea sediments (DSS) produced a large number of micrometeorites, in particular, iron-rich cosmic spherules that are rarer in other collections. Collections from the old and stable surface of the Atacama Desert show that finding large numbers of micrometeorites is not restricted to polar regions or DSS. The advent of rooftop collections marks an important step into involving citizen science in the study of micrometeorites, as well as providing potential sampling locations over all latitudes to explore the modern flux. We explore their strengths of the collections to address specific scientific questions and their potential weaknesses. The future of micrometeorite research will involve the finding of large fossil micrometeorite collections and benefit from recent advances in sampling cosmic dust directly from the air. This article is part of the theme issue 'Dust in the Solar System and beyond'. [ABSTRACT FROM AUTHOR]

Exposure of the Hubble Space Telescope to space in low Earth orbit resulted in numerous hypervelocity impacts by cosmic dust (micrometeoroids) and anthropogenic particles (orbital debris) on the solar arrays and the radiator shield of the Wide Field and Planetary Camera 2, both subsequently returned to Earth. Solar cells preserve residues from smaller cosmic dust (and orbital debris) but give less reliable information from larger particles. Here, we present images and analyses from electron, ion and X-ray fluorescence microscopes for larger impact features (millimetre- to centimetre-scale) on the radiator shield. Validated by laboratory experiments, these allow interpretation of composition, probable origin and likely dimensions of the larger impactors. The majority (~90%) of impacts by grains greater than 50 μm in size were made by micrometeoroids, dominated by magnesium- and iron-rich silicates and iron sulfides, metallic iron-nickel and chromium-rich spinel similar to that in ordinary chondrite meteorites of asteroid origin. Our re-evaluation of the largest impact features shows substantially fewer large orbital debris impacts than reported by earlier authors. Mismatch to the NASA ORDEM and ESA MASTER models of particle populations in orbit may be partly due to model overestimation of orbital debris flux and underestimation of larger micrometeoroid numbers. This article is part of the theme issue 'Dust in the Solar System and beyond'. [ABSTRACT FROM AUTHOR]

Cosmological simulations serve as invaluable tools for understanding the Universe. However, the technical complexity and substantial computational resources required to generate such simulations often limit their accessibility within the broader research community. Notable exceptions exist, but most are not suited for simultaneously studying the physics of galaxy formation and cosmic reionization during the first billion years of cosmic history. This is especially relevant now that a fleet of advanced observatories (e.g. James Webb Space Telescope, Nancy Grace Roman Space Telescope , SPHEREx, ELT, SKA) will soon provide an holistic picture of this defining epoch. To bridge this gap, we publicly release all simulation outputs and post-processing products generated within the thesan simulation project at www.thesan-project.com. This project focuses on the z ≥ 5.5 Universe, combining a radiation-hydrodynamics solver (arepo-rt), a well-tested galaxy formation model (IllustrisTNG) and cosmic dust physics to provide a comprehensive view of the Epoch of Reionization. The thesan suite includes 16 distinct simulations, each varying in volume, resolution, and underlying physical models. This paper outlines the unique features of these new simulations, the production and detailed format of the wide range of derived data products, and the process for data retrieval. Finally, as a case study, we compare our simulation data with a number of recent observations from the James Webb Space Telescope , affirming the accuracy and applicability of thesan. The examples also serve as prototypes for how to utilize the released data set to perform comparisons between predictions and observations. [ABSTRACT FROM AUTHOR]

Cosmic plasmas are considered as the most abundant form of ordinary matter in the Universe while observations of the cosmic dust in different regions provide an insight into the Universe's recycling processes. For different types of the cosmic dusty plasmas, we hereby, with the symbolic computation and observational/experimental supports, study a (3+1)-dimensional generalized variable-coefficient Kadomtsev-Petviashvili-Burgers-type equation, which can describe the electron-acoustic, dust-acoustic, positron-acoustic, dust-magneto-acoustic, ion-acoustic, magneto-acoustic, ion, quantum-dust-ion-acoustic or dust-ion-acoustic waves in one of the cosmic/laboratory dusty plasmas. With respect to the fluctuation of the electron or ion density, or perturbation of the magnitude of the magnetic field, or electrostatic wave potential, or radial-direction component of the velocity of ions or dust particles, a set of the auto-Bäcklund transformations, several soliton families and a set of the similarity reductions are symbolically computed out, depending on the variable coefficients which represent the dispersion, nonlinearity, geometric effect, Burgers/dusty-fluid-viscosity dissipation and diffraction/transverse perturbation. Variable-coefficient constraints on the soliton solutions are presented. Our analytic results are in agreement with those dusty-plasma-experimentally reported. Future dusty-plasma experiments and observations might justify some other effects hereby offered. [ABSTRACT FROM AUTHOR]

Cosmic dust particles originate from a wide variety of solar system and interstellar objects, including sources not identified among meteorite collections. Particles that survive atmospheric entry are retrieved on the Earth's surface as micrometeorites. The recovery of these micrometeorites has recently advanced to rooftop sites. Here, we present the results of an extensive isotopic study on this type of rooftop micrometeorite from the Budel collection, the Netherlands, accreted to the Earth between October 31, 2018 and June 16, 2021. The triple oxygen isotopic compositions of 80 silica‐dominated cosmic spherules (CSs) with diameters ranging between 105 and 515 μm are obtained relying on 213 in situ spot analyses determined using ion microprobe. Our analyzed population spans a large range of isotopic compositions and is dominated by carbonaceous chondritic sources. In situ measurements on several CSs support a possible continuum between 16O‐rich and 16O‐poor compositions following the CM mixing line, showing that 16O‐poor CSs may be genetically related to aqueously altered carbonaceous chondrites. We demonstrate that weathering in the terrestrial environment has negligible effects on the isotopic compositions of the studied CSs and attempt to quantify the effects of kinetic mass‐dependent fractionation and admixture of terrestrial oxygen during atmospheric entry. The results further corroborate previously suggested relations between CS texture and the duration and intensity of the heating pulse experienced during atmospheric deceleration. Finally, the young and well‐constrained terrestrial age of the collection provides insights into the most recent flux of cosmic dust. Our results indicate no major recent changes in the global flux compared with collections sampled over thousand‐ to million‐year time scales and demonstrate that 16O‐poor material is still represented in the modern‐day cosmic dust flux at a relative abundance of ~13%–15%. As such, rooftop micrometeorites represent a valuable reservoir to study the characteristics of the contemporary cosmic dust flux. [ABSTRACT FROM AUTHOR]

The interplay between extraterrestrial, atmospheric, aqueous, interfacial, and hydrothermal processes is crucial for Earth's prebiotic chemistry. Volcanic terrains contain polyoxometalates (POMs). Some polyoxocuprates were identified as building blocks of fumarole minerals produced from high‐temperature gases. The existence of polyoxovanadate anions in acidified reducing volcanic aquifers cannot be excluded. At present, it can only be speculated whether life arose around natural POM deposits and/or around their aqueous phase chemistry through acid‐base and/or redox reactions. This Commentary spans different fields of sciences in nature cybernetic loop to provide impetus to explore gas‐phase chemical reactions of multiply charged POM ions, catalysis by POM‐containing mineral phases, the behavior of POMs under plasma‐initiated ultraviolet photolysis, interactions of POMs with microorganisms, bioorthogonal chemistry of POMs, and engineering POM‐based bionic functions inspired by living organisms. [ABSTRACT FROM AUTHOR]

A recent study published in eLife suggests that changes in neural activity associated with brain aging may be influenced by signals from the heart. The researchers found that cardiac signals can contaminate brain recordings, leading to misinterpretation of age-related changes in brain activity. The study also revealed a complex pattern of age-related changes in aperiodic neural activity, which may be driven by both cardiac and neural factors. These findings highlight the need for more sophisticated models to accurately account for all potential sources of noise in brain recordings. [Extracted from the article]

The large-scale environment of the cosmic web is believed to impact galaxy evolution, but there is still no consensus regarding the mechanisms. We use a semi-analytic model (SAM) galaxy catalog to study the star formation and dust content of local galaxies in different cosmic environments of the cosmic web—namely voids, filaments, walls, and nodes. We find a strong impact of the environment only for galaxies with M stars ≲ 1010.8 M ⊙: the less dense the environment, the larger the star formation rate and dust content at fixed stellar mass. This is attributed to the fact that galaxies in less dense environments typically feature younger stellar populations, a slower evolution of their stellar mass, and delayed star formation compared to galaxies in denser environments. As for galaxies with M stars ≳ 1010.8 M ⊙, the differences among environments are milder, due to the disk-instability-driven supermassive black hole (SMBH) growth implemented in the SAM, which makes SMBH growth, and thus galaxy quenching, environment-insensitive. We qualitatively test our predictions against observations by identifying environments in Sloan Digital Sky Survey Data Release 16 using dust masses derived from the GAMA survey. The agreement is encouraging, particularly at log M stars / M ⊙ ≳ 10.5 – 11 , where the specific star formation rates and dust masses appear quite environment-insensitive. This result confirms the importance of in situ growth channels of SMBHs. [ABSTRACT FROM AUTHOR]

Context. Thermal diffusion is one of the basic processes for the mobility and formation of species on cosmic dust grains. The rate of thermal diffusion is determined by the grain surface temperature, a pre-exponential factor, and an activation energy barrier for diffusion. Due to the lack of laboratory measurements on diffusion, prior astrochemical models usually assume that the diffusion pre-exponential factor is the same as that for desorption. This oversimplification may lead to an uncertainty in the model predictions. Recent laboratory measurements have found that the diffusion pre-exponential factor can differ from that for desorption by several orders of magnitude. However, the newly determined pre-exponential factor has not been tested in astrochemical models so far. Aims. We aim to evaluate the effect of the newly experimentally measured diffusion pre-exponential factor on the chemistry under cold molecular cloud conditions. Methods. We ran a set of parameters with different grain temperatures and diffusion barrier energies using the NAUTILUS astro-chemical code and compared the molecular abundance between the models with the abundance obtained using the experimentally determined pre-exponential factor for diffusion and with the abundance obtained using the values commonly adopted in prior models. Results. We found that statistically, more than half of the total gas-phase and grain surface species are not affected by the new pre-exponential factor after a chemical evolution of 105 yr. The most abundant gas-phase CO and grain surface water ice are not affected by the new pre-exponential factor. For the grain surface species that are affected, compared to the commonly adopted value of the pre-exponential factor for diffusion used in the chemical models, they could be either overproduced or underproduced with the lower diffusion pre-factor used in this work. The former case applies to radicals and the species that serve as reactants, while the latter case applies to complex organic molecules (COMs) on the grain and the species that rarely react with other species. Gas-phase species could also be affected due to the desorption of the grain surface species. The abundance of some gas-phase COMs could be varied by over one order of magnitude depending on the adopted grain surface temperature and/or the ratio of diffusion to desorption energy in the model. Key species whose diffusion pre-exponential factor significantly affects the model predictions were also evaluated, and these species include CH3OH, H2CO, and NO. Conclusions. The results presented in this study show that the pre-exponential factor is one of the basic and important parameters in astrochemical models. It strongly affects the chemistry and should be determined carefully. More experiments to determine the diffusion of grain surface species are helpful for constraining their properties. [ABSTRACT FROM AUTHOR]

Context. High-resolution 3D maps of interstellar dust are critical for probing the underlying physics shaping the structure of the interstellar medium, and for foreground correction of astrophysical observations affected by dust. Aims. We aim to construct a new 3D map of the spatial distribution of interstellar dust extinction out to a distance of 1.25 kpc from the Sun. Methods. We leveraged distance and extinction estimates to 54 million nearby stars derived from the Gaia BP/RP spectra. Using the stellar distance and extinction information, we inferred the spatial distribution of dust extinction. We modeled the logarithmic dust extinction with a Gaussian process in a spherical coordinate system via iterative charted refinement and a correlation kernel inferred in previous work. In total, our posterior has over 661 million degrees of freedom. We probed the posterior distribution using the variational inference method MGVI. Results. Our 3D dust map has an angular resolution of up to 14′ (Nside = 256), and we achieve parsec-scale distance resolution, sampling the dust in 516 logarithmically spaced distance bins spanning 69 pc to 1250 pc. We generated 12 samples from the variational posterior of the 3D dust distribution and release the samples alongside the mean 3D dust map and its corresponding uncertainty. Conclusions. Our map resolves the internal structure of hundreds of molecular clouds in the solar neighborhood and will be broadly useful for studies of star formation, Galactic structure, and young stellar populations. It is available for download in a variety of coordinate systems online and can also be queried via the publicly available dustmaps Python package. [ABSTRACT FROM AUTHOR]

Before the end of its mission, the Cassini spacecraft orbited Saturn in a series of highly inclined elliptical 'Ring-Grazing' orbits (RGO). During the RGO, the spacecraft passed repeatedly through the ring plane outside the F ring, near the orbits of Janus and Epimetheus, at an average relative speed of ∼20 km s–1. For the first time, Cassini's Cosmic Dust Analyser (CDA) directly sampled dust particles from this region. Here, we analyse the compositions of dust grains sampled within ±15 min relative to nine ring plane crossings of the RGO. The compositions of most analysed RGO grains are similar to those of E ring ice grains, implying that the E ring extends to within at least 2.45 Saturn radii (RS) of Saturn. The compositional distribution of these grains point at a similar average period (decades) since ejection from Enceladus as of particles in the outer E ring (beyond 8 RS). Higher fractions of larger grains are found near the orbits of Janus and Epimetheus, which probably represent ejecta from these moons. Most of these grains have compositions similar to the background E ring grains, indicating that E ring material is coating the surfaces of Janus and Epimetheus. We also report the detection of several types of mineral grains on prograde orbits, one of which, a water ice/silicate mixture, has never been observed by CDA elsewhere. These mineral grains appear to have a different origin from the E ring, and may arise from nearby moons, the F ring, or main rings. [ABSTRACT FROM AUTHOR]

Dust-obscured star formation has dominated the cosmic history of star formation, since z ≃ 4 . However, the recent finding of significant amount of dust in galaxies out to z ≃ 8 has opened the new frontier of investigating the origin of dust also in the earliest phases of galaxy formation, within the first 1.5 billion years from the Big Bang. This is a key and rapid transition phase for the evolution of dust, as galaxy evolutionary timescales become comparable with the formation timescales of dust. It is also an area of research that is experiencing an impressive growth, especially thanks to the recent results from cutting edge observing facilities, ground-based, and in space. Our aim is to provide an overview of the several findings on dust formation and evolution at z > 4 , and of the theoretical efforts to explain the observational results. We have organized the review in two parts. In the first part, presented here, we focus on dust sources, primarily supernovae and asymptotic giant branch stars, and the subsequent reprocessing of dust in the interstellar medium, through grain destruction and growth. We also discuss other dust production mechanisms, such as Red Super Giants, Wolf–Rayet stars, Classical Novae, Type Ia Supernovae, and dust formation in quasar winds. The focus of this first part is on theoretical models of dust production sources, although we also discuss the comparison with observations in the nearby Universe, which are key to put constraints on individual sources and processes. While the description has a general applicability at any redshift, we emphasize the relative role of different sources in the dust build-up in the early Universe. In the second part, which will be published later on, we will focus on the recent observational results at z > 4 , discussing the theoretical models that have been proposed to interpret those results, as well as the profound implications for galaxy formation. [ABSTRACT FROM AUTHOR]

During the Grand Finale orbits, Cassini's Cosmic Dust Analyzer (CDA) recorded in situ mass spectra of ice and mineral nanodust grains ejected from Saturn's main rings falling into the planet's atmosphere. We present a compositional analysis of the mineral dust fraction employing a spectral deconvolution method to determine the elemental composition of these grains. The results indicate a relatively homogenous composition of exclusively Mg-rich silicates, with Mg, Si, and Ca close to CI chondritic abundances but a significant depletion in Fe and only traces of organic material at best. The Fe depletion becomes even more pronounced when compared to Fe-rich interplanetary dust particles encountered by CDA in the Saturnian system, which are assumed to contaminate and darken the main rings over time. We discuss potential explanations for the depletion, from which we favour compositional alteration of the infalling dust grains by impact-triggered chemistry in combination with dynamical selection effects and instrumental bias as the most plausible ones. This might cause an accumulation of Fe in the main rings over time, most likely in the form of oxides. [ABSTRACT FROM AUTHOR]

Since the first automatic missions to the Moon, the activity of dust particles from atmosphereless bodies has been recorded. Since then, a lot of theoretical and experimental studies of this effect have been carried out, but at present there is no clear understanding of the influence of external actions on the dynamics of this phenomenon. This paper presents the results of experiments to determine the effect of hard UV radiation on the activity of dust particles, which makes a significant contribution to particle dynamics. The result of determining the conditions for particle removal from the surface is in accordance with theoretical calculations. [ABSTRACT FROM AUTHOR]

The article proposes a new method for estimating the number of particles in experiments on modeling the interaction of cosmic and lunar dust with the surface of spacecraft. The experiments are based on the creation of a dusty plasma cloud, when exposed to radiation from a powerful pulsed gyrotron on a substance simulating cosmic or lunar dust. This approach was tested using a lunar regolith simulator. The dynamics of particles in dust clouds obtained as a result of microwave discharge is analyzed using the ImageJ program. [ABSTRACT FROM AUTHOR]

To understand the origin of dust in the circum-galactic medium (CGM), we develop a dust enrichment model. We describe each of the central galaxy and its CGM as a single zone, and consider the mass exchange between them through galactic inflows and outflows. We calculate the evolution of the gas, metal, and dust masses in the galaxy and the CGM. In the galaxy, we include stellar dust production and interstellar dust processing following our previous models. The dust in the galaxy is transported to the CGM via galactic outflows, and it is further processed by dust destruction (sputtering) in the CGM. We parametrize the time-scale or efficiency of each process and investigate the effect on the dust abundance in the CGM. We find that the resulting dust mass is sensitive to the dust destruction in the CGM, and the dust supply from galactic outflows, both of which directly regulate the dust abundance in the CGM. The inflow time-scale also affects the dust abundance in the CGM because it determines the gas mass evolution (thus, the star formation history) in the galaxy. The dust abundance in the CGM, however, is insensitive to stellar dust formation in the galaxy at later epochs because the dust production is dominated by dust growth in the interstellar medium. We also find that the resulting dust mass in the CGM is consistent with the value derived from a large sample of SDSS galaxies. [ABSTRACT FROM AUTHOR]

Abstract The interplay between extraterrestrial, atmospheric, aqueous, interfacial, and hydrothermal processes is crucial for Earth's prebiotic chemistry. Volcanic terrains contain polyoxometalates (POMs). Some polyoxocuprates were identified as building blocks of fumarole minerals produced from high‐temperature gases. The existence of polyoxovanadate anions in acidified reducing volcanic aquifers cannot be excluded. At present, it can only be speculated whether life arose around natural POM deposits and/or around their aqueous phase chemistry through acid‐base and/or redox reactions. This Commentary spans different fields of sciences in nature cybernetic loop to provide impetus to explore gas‐phase chemical reactions of multiply charged POM ions, catalysis by POM‐containing mineral phases, the behavior of POMs under plasma‐initiated ultraviolet photolysis, interactions of POMs with microorganisms, bioorthogonal chemistry of POMs, and engineering POM‐based bionic functions inspired by living organisms.

Atacama Large Millimeter/submillimeter Array (ALMA) observations revealed the presence of significant amounts of dust in the first Gyr of Cosmic time. However, the metal and dust build-up picture remains very uncertain due to the lack of constraints on metallicity. JWST has started to reveal the metal content of high-redshift targets, which may lead to firmer constraints on high-redshift dusty galaxies evolution. In this work, we use detailed chemical and dust evolution models to explore the evolution of galaxies within the ALMA Reionization Era Bright Emission Line Survey (REBELS) survey, testing different metallicity scenarios that could be inferred from JWST observations. In the models, we track the build-up of stellar mass using non-parametric star formation histories for REBELS galaxies. Different scenarios for metal and dust evolution are simulated by allowing different prescriptions for gas flows and dust processes. The model outputs are compared with measured dust scaling relations, by employing metallicity-dependent calibrations for the gas mass based on the [C  ii ] 158  μ m line. Independently of the galaxies metal content, we found no need for extreme dust prescriptions to explain the dust masses revealed by ALMA. However, different levels of metal enrichment will lead to different dominant dust production mechanisms, with stardust production dominant over other interstellar medium dust processes only in the metal-poor case. This points out how metallicity measurements from JWST will significantly improve our understanding of the dust build-up in high-redshift galaxies. We also show that models struggle to reproduce observables such as dust-to-gas and dust-to-stellar ratios simultaneously, possibly indicating an overestimation of the gas mass through current calibrations, especially at high metallicities. [ABSTRACT FROM AUTHOR]

We report the detection of cold dust in an apparently quiescent massive galaxy (log (M ⋆/M⊙) ≈ 11) at z ∼ 2 (G4). The source is identified as a serendipitous 2 mm continuum source in a deep ALMA observation within the field of Q2343-BX610, a z  = 2.21 massive star-forming disc galaxy. Available multiband photometry of G4 suggests redshift of z ∼ 2 and a low specific star formation rate (sSFR), log (SFR/ M ⋆)[yr−1] ≈ −10.2, corresponding to ≈1.2 dex below the z  = 2 main sequence (MS). G4 appears to be a peculiar dust-rich quiescent galaxy for its stellar mass (log (M dust/ M ⋆) = −2.71 ± 0.26), with its estimated mass-weighted age (∼1–2 Gyr). We compile z ≳ 1 quiescent galaxies in the literature and discuss their age–ΔMS and log (M dust/ M ⋆)–age relations to investigate passive evolution and dust depletion scale. A long dust depletion time and its morphology suggest morphological quenching along with less efficient feedback that could have acted on G4. The estimated dust yield for G4 further supports this idea, requiring efficient survival of dust and/or grain growth, and rejuvenation (or additional accretion). Follow-up observations probing the stellar light and cold dust peak are necessary to understand the implication of these findings in the broader context of galaxy evolutionary studies and quenching in the early universe. [ABSTRACT FROM AUTHOR]

Saturn's large and diffuse E ring is populated by microscopic water ice dust particles, which originate from the Enceladus plume. Cassini 's Cosmic Dust Analyser sampled these ice grains, revealing three compositional particle types with different concentrations of salts and organics. Here, we present the analysis of CDA mass spectra from several orbital periods of Cassini , covering the region from interior to Enceladus' orbit to outside the orbit of Rhea, to map the distribution of the different particle types throughout the radial extent of the E ring. This will provide a better understanding of the potential impact of space weathering effects on to these particles, as the ice grains experience an increasing exposure age during their radially outward migration. In this context, we report the discovery of a new ice particle type (Type 5), which produces spectra indicative of very high salt concentrations, and which we suggest to evolve from less-salty Enceladean ice grains by space weathering. The radial compositional profile, now encompassing four particle types, reveals distinct radial variations in the E ring. At the orbital distance of Enceladus our results are in good agreement with earlier compositional analyses of E ring ice grains in the moon's vicinity. With increasing radial distance to Saturn however, our analysis suggests a growing degree of space weathering and considerable changes to the spatial distribution of the particle types. We also find that the proportion of Type 5 grains – peaking near Rhea's orbit – probably reflects particle charging processes in the E ring. [ABSTRACT FROM AUTHOR]

We present a cross-correlation analysis between 1 ′ resolution total intensity and polarization observations from the Atacama Cosmology Telescope (ACT) at 150 and 220 GHz and 15″ mid-infrared photometry from the Wide-field Infrared Survey Explorer (WISE) over 107 12.°5 × 12.°5 patches of sky. We detect a spatially isotropic signal in the WISE×ACT TT cross-power spectrum at 30 σ significance that we interpret as the correlation between the cosmic infrared background at ACT frequencies and polycyclic aromatic hydrocarbon (PAH) emission from galaxies in WISE, i.e., the cosmic PAH background. Within the Milky Way, the Galactic dust TT spectra are generally well described by power laws in ℓ over the range 103 < ℓ < 104, but there is evidence both for variability in the power-law index and for non-power-law behavior in some regions. We measure a positive correlation between WISE total intensity and ACT E -mode polarization at 1000 < ℓ ≲ 6000 at >3 σ in each of 35 distinct ∼100 deg2 regions of the sky, suggesting that alignment between Galactic density structures and the local magnetic field persists to subparsec physical scales in these regions. The distribution of TE amplitudes in this ℓ range across all 107 regions is biased to positive values, while there is no evidence for such a bias in the TB spectra. This work constitutes the highest- ℓ measurements of the Galactic dust TE spectrum to date and indicates that cross-correlation with high-resolution mid-infrared measurements of dust emission is a promising tool for constraining the spatial statistics of dust emission at millimeter wavelengths. [ABSTRACT FROM AUTHOR]

The relationship between spikes in cosmic dust fluxes onto the Earth's surface (mainly represented by native metal particles) and the behavior of the polarity of the main geomagnetic field has been studied. For this, a search was carried out for horizons of paleodeposits with a high concentration of cosmic dust (exceeding the background concentration by more than an order of magnitude). Such increased concentrations of cosmic dust particles were found in peat deposits corresponding to the Etrussia excursion (2.5–3 ka), as well as in ancient Cretaceous and Paleogene marine deposits. In total, we discovered five horizons with a thickness up to 1 m hosting a high concentration of cosmic dust. Measurements of the paleo‒and petromagnetic parameters of samples selected based on the thickness of sedimentary strata showed that the beginning of accumulation of these horizons coincided with geomagnetic field excursions. In this case, sediment enrichment in dust particles could have lasted somewhat longer than a geomagnetic field excursion. Evidence was obtained that Earth collisions with dense fluxes of cosmic dust could have coincided with short-term disturbances in the polarity of the geomagnetic field, but this had no lasting effect on the geodynamo. [ABSTRACT FROM AUTHOR]

We study the behaviour of dust in galaxies at cosmic dawn, z  = 6–8, by coupling the FirstLight simulations with the radiative transfer code polaris. The starburst nature of these galaxies and their complex distribution of dust lead to a large diversity of attenuation curves. These follow the Calzetti model only for relatively massive galaxies, M stars ≃ 109 M⊙. Galaxies with lower masses have steeper curves, consistent with the model for the Small Magellanic Cloud. The ultraviolet and optical slopes of the attenuation curves are closer to the modified Calzetti model, with a slight preference for the power-law model for galaxies with the highest values of attenuation. We have also examined the relation between the slope in the far-ultraviolet, βUV, and the infrared excess, IRX. At z  = 6, it follows the Calzetti model with a shift to slightly lower βUV values due to lower metallicities at lower attenuation. The same relation at z  = 8 shows a shift to higher IRX values due to a stronger CMB radiation at high z. [ABSTRACT FROM AUTHOR]

In recent years, evidence has been obtained that in the outer region of the Solar System (in the inner Oort cloud) at a distance of ~300–700 AU from the Sun, there may be a captured planet or a primordial black hole. In this paper, we show that the gravitational scattering on this object of dust particles located in the same region can transfer them to new elongated orbits reaching the Earth's orbit. With the mass of the captured object on the order of 5–10 Earth masses, the calculated dust flow near the Earth is ~0.1–3 µg m–2 year–1 is comparable in order of magnitude with the observed flow. This effect gives a joint restriction on the parameters of the captured object and on the amount of dust in the Oort cloud. [ABSTRACT FROM AUTHOR]

Large increases in the number of low earth orbit satellites are projected in the coming decades [L. Schulz, K.-H. Glassmeier, Adv. Space Res. 67, 1002–1025 (2021)] with perhaps 50,000 additional satellites in orbit by 2030 [GAO, Large constellations of satellites: Mitigating environmental and other effects (2022)]. When spent rocket bodies and defunct satellites reenter the atmosphere, they produce metal vapors that condense into aerosol particles that descend into the stratosphere. So far, models of spacecraft reentry have focused on understanding the hazard presented by objects that survive to the surface rather than on the fate of the metals that vaporize. Here, we show that metals that vaporized during spacecraft reentries can be clearly measured in stratospheric sulfuric acid particles. Over 20 elements from reentry were detected and were present in ratios consistent with alloys used in spacecraft. The mass of lithium, aluminum, copper, and lead from the reentry of spacecraft was found to exceed the cosmic dust influx of those metals. About 10% of stratospheric sulfuric acid particles larger than 120 nm in diameter contain aluminum and other elements from spacecraft reentry. Planned increases in the number of low earth orbit satellites within the next few decades could cause up to half of stratospheric sulfuric acid particles to contain metals from reentry. The influence of this level of metallic content on the properties of stratospheric aerosol is unknown. [ABSTRACT FROM AUTHOR]

Linking meteorites to their asteroid parent bodies remains an outstanding issue. Space‐based dust characterization using impact ionization mass spectrometry is a proven technique for the compositional analysis of individual cosmic dust grains. Here we investigate the feasibility of determining asteroid compositions via cation mass spectrometric analyses of their dust ejecta clouds during low (7–9 km s−1) velocity spacecraft flybys. At these speeds, the dust grain mass spectra are dominated by easily ionized elements and molecular species. Using known bulk mineral volume abundances, we show that it is feasible to discriminate the common meteorite classes of carbonaceous chondrites, ordinary chondrites, and howardite–eucrite–diogenite achondrites, as well as their subtypes, relying solely on the detection of elements with ionization efficiencies of ≤700 or ≤800 kJ mol−1, applicable to low (~7 km s−1) and intermediate (~9 km s−1) flyby speed scenarios, respectively. Including the detection of water ion groups enables greater discrimination between certain meteorite types, and flyby speeds ≥10 km s−1 enhance the diagnostic capabilities of this technique still further. Although additional terrestrial calibration is required, this technique may allow more unequivocal asteroid‐meteorite connections to be determined by spacecraft flybys, emphasizing the utility of dust instruments on future asteroid missions. [ABSTRACT FROM AUTHOR]

We have discovered that the peak phase time of predawn thermosphere‐ionosphere Na (TINa) layers (∼110–150 km altitude) undergoes clear annual variations with the earliest occurrence in summer and latest in winter over Boulder (40.13°N, 105.24°W), which are closely correlated to annual phase variations of sunrise and tidal winds. Such discoveries were enabled by the first characterization of 12 monthly composites of TINa layers from January through December using 7 years of lidar observations (2011–2017). Despite their tenuous densities, the predawn TINa layers have nearly 100% occurrence rate (160 out of 164 nights of observations). Monthly composites show downward‐phase‐progression TINa descending at similar phase speeds as Climatological Tidal Model of the Thermosphere tidal winds. These TINa layers occur in ion convergence but neutral divergence regions, modeled using tidal winds. These results support the formation mechanism (neutralization of converged TINa+ forming TINa) proposed previously and suggest that migrating tidal winds experience annual phase variations. Plain Language Summary: With tons of cosmic dust falling on Earth every day, metallic atoms and ions (e.g., Fe, Na, K, and Ca+) are released via meteor ablation and sputtering into the upper atmosphere, forming permanent metal layers (∼75–105 km) that have been known for nearly a century. What was unknown until 2011 was the existence of thermosphere‐ionosphere metal (TIMt) layers that were discovered with high‐sensitivity lidar observations first from Antarctica and then were observed globally. These neutral TIMt layers locate above the permanent layers with an upper reach to ∼200 km and exhibit intermittent occurrence. In 2021 surprising regular occurrence of TIMt layers in Na species (TINa) was reported for the first time from lidar observations over Boulder, Colorado, where TINa layers occur before dawn and after dusk nearly every night. By analyzing 7 years of lidar data, we have further discovered that the Boulder predawn TINa layers occur in earlier hours in summer than in winter. Such annual phase variations are correlated with sunrise and solar‐heating‐driven tidal winds. These TIMt layers are of great scientific interest as they provide unique tracers for making direct measurements in the least understood but crucially important "thermospheric gap" region of 100–200 km. Key Points: First characterization of 12 monthly composites of Na mixing ratios reveals annual phase variations of predawn thermosphere‐ionosphere Na (TINa) layers (110–150 km)Predawn TINa occur ∼2.5 hr earlier in summer than in winter, closely correlating to annual phase variations of sunrise and Climatological Tidal Model of the Thermosphere semidiurnal westward‐propagating tidal windsTINa layers descend at similar rates as and in tidal‐wind‐modeled ion convergence regions, supporting neutralization of TINa+ forming TINa [ABSTRACT FROM AUTHOR]

Beginning some 30,000 years ago, nine of our Paleolithic ancestors painted their unique hands on the walls of Altamira Cave in Cantabria, Spain – an act of communication by the community, for the community. We present a proof-of-concept for the Altamira Comet, a 21st century work that expresses the evolution of this gesture in our digital age: we all go. The Altamira Comet invites everyone on Earth to participate, individually and uniquely, through our contemporary society's iconic representation of identity: the selfie. Everyone's selfies will be cast as microscopic low relief golden busts, frozen into a ball of ice, and deployed into heliocentric orbit as a sublimating comet, embodying millions of individual humans from around the world. The proof-of-concept is a vial of five million discrete selfie sculptures in solution, using computer vision, electron-beam lithography and high-vacuum deposition to fabricate each selfie the size of a grain of cosmic dust. We also discuss plans to deploy the comet using an off-the-shelf CubeSat deployer and to scale the work to support a goal of at least one billion global participants. • Space art in the form of a comet. • Global art that invites everyone on Earth to participate. • Inspired by prehistoric hand art on the walls of Altamira Cave. • Multidisciplinary art combining computer vision, e-beam lithography, comets and CubeSats. [ABSTRACT FROM AUTHOR]

Introduction: Recent observations indicate that the Universe is not transparent but partially opaque due to absorption of light by ambient cosmic dust. This implies that the current cosmological model valid for the transparent universe must be modified for the opaque universe. Objectives: The paper studies a scenario of the evolution of the Universe when the cosmic opacity steeply rises with redshift, because the volume of the Universe was smaller and the cosmic dust density was higher in the previous epochs. In this case, the light-matter interactions become important, because cosmic opacity produces radiation pressure that counterbalances gravitational forces. Methods: The radiation pressure due to cosmic opacity is evaluated and incorporated into the Friedmann equations, which describe cosmic dynamics. The equations are based on the conformal FLRW metric and are consistent with observations of the cosmological redshift as well as time dilation. Using astronomical observations of basic cosmological parameters, the solution of the modified Friedmann equations is numerically modelled. Results: The presented model predicts a cyclic expansion/contraction evolution of the Universe within a limited range of scale factors with no Big Bang. The redshift of the Universe with the minimum volume is about 15–17. The model avoids dark energy and removes several fundamental tensions of the standard cosmological model. In agreement with observations, the modified Friedmann equations predict the existence of very old mature galaxies at high redshifts and they do not limit the age of stars in the Universe. The new model is consistent with theory of cosmic microwave background as thermal radiation of cosmic dust. Conclusion: The paper demonstrates that considering light-matter interactions in cosmic dynamics is crucial and can lead to new cosmological models essentially different from the currently accepted ΛCDM model.

Linda Martel has been awarded the 2018 Service Award for her contributions to Planetary Science Research Discoveries (PSRD), a website that explains the discoveries made through the study of extraterrestrial materials. PSRD aims to share scientific discoveries in meteoritics and planetary science with a wide audience, and has become an internationally recognized source of information in the field. Linda Martel, who co-founded PSRD and has been the sole webmaster for over 20 years, has played a crucial role in its success by writing and editing numerous articles and ensuring the website's functionality and appearance keep up with evolving technology. [Extracted from the article]

We present an empirical analysis of the properties of dust-continuum emission in a sample of 17 galaxies in the early Universe (4 < z < 8) with well-sampled far-infrared spectral energy distributions (SEDs) compiled from the literature. We place our results into context by self-consistently comparing to samples of nearby star-forming galaxies, luminous infrared galaxies (LIRGs), and quasars. With the exception of two sources, we find no significant evolution in the dust emissivity index across cosmic time, measuring a consistent value of βIR = 1.8 ± 0.3 at z > 4, suggesting that the effective dust properties do not change dramatically for most galaxies. Despite having comparable stellar masses, we find the high-redshift galaxies to be similar to, or even more extreme than, LIRGs in the Herschel (U)LIRG Survey, where (U)LIRG refers to (ultra-)LIRG, sample in terms of dust temperature (⁠|$T_\text{dust} \gt 40 \, \mathrm{K}$|⁠) and infrared (IR) luminosity (⁠|$L_\text{IR} \gt 10^{11} \, \mathrm{L_\odot }$|⁠). We find that the dust temperature evolves mildly towards high redshift, though the LIRGs and quasars exhibit elevated temperatures indicating a more efficient and/or additional heating mechanism. Where available, we compare stellar mass estimates to our inferred dust masses, whose degeneracy with dust temperature can only be mitigated with a well-constrained SED. In merely half of the cases, the dust yield may be explained by supernovae alone, with four sources (⁠|$44{{\ \rm per\ cent}}$|⁠) significantly exceeding a highly optimistic yield where M dust ≈ 0.01 M *. We discuss possible explanations for this apparent inconsistency and potential observational biases in the measurements of the dust properties of high-redshift galaxies, including in the current IR-bright sample. [ABSTRACT FROM AUTHOR]

In last times the dynamic development of astrophysics studied the interaction of matter and radiation on cosmos space, as well as the appearance of new possibilities of observation of celestial bodies allow to investigate the physical processes in the interstellar medium in detail. The density and quantity of interstellar gas and dust determine the possibility of new star formation, meanwhile star changes the properties of the surrounding interstellar medium, they heat it, support the continues movement of gas and supplement the medium with their own matter and change their chemical composition. In the present work, the first searches of young stellar objects were carried out in the region of the infrared duct bubble N19 and also there were created the program for searching of new stellar objects in computer simulation by MatLab. 11 objects were attributed to the young stars of I class by the found sources of infrared radiation, 26 objects to the II class and 20 objects are regarded to the young stars at the stage of transition disks. As a result, "a color-color" diagram for young stellar objects candidates detected near the infrared dust bubble N19 was constructed. In addition, there were analyzed the ranges of variation of the color indices and that diagram allows to determine the new criteria for determination of the new star objects in accordance with the stage of their evolution. [ABSTRACT FROM AUTHOR]

Molecular hydrogen (H2) has nuclear spin isomers: ortho-H2 and para-H2. Under the isolated condition, the nuclear spin conversion (NSC) between these isomers is forbidden. The ortho-to-para ratio, OPR, of H2 is important in chemistry and physics of interstellar media. The OPR in space has been considered to evolve only via the gas phase reactions with proton and hydrogen atoms. Because interstellar H2 is produced predominantly on the surface of cosmic dust and gaseous H2 molecules inevitably collide with dust, the NSC process on the surface of cosmic dust should be quantitatively qualified to know the evolution of OPR. Recently, we revealed that the H2 NSC occurs on cosmic dust analogs within laboratory timescale. In this article, we introduce the methods for observing NSC processes, the NSC time constants determined for the surfaces of amorphous solid water, amorphous-Mg2SiO4, and diamond-like carbon at low temperatures, and implication of the results to astrophysics. [ABSTRACT FROM AUTHOR]

The violent stellar explosions known as supernovae have received especially strong attention in both the research community and the general public recently. With the advent of space telescopes, the study of these extraordinary events has switched gears and it has become one of the leading fields in modern astrophysics. In this paper, we review some of the recent developments, focusing mainly on studies related to space-based observations. [ABSTRACT FROM AUTHOR]

Observations suggest that the amount of galactic dust in the Universe decreased by a factor of ∼2–3 during the last ∼8 Gyr. However, cosmological models of galaxy evolution usually struggle to explain this decrease. Here, we use the semi-analytic model (SAM) L-Galaxies2020 to show that this drop may be reproduced assuming standard prescriptions for dust production and evolution. We extend the SAM with (i) a state-of-the-art dust model that adopts the two-size approximation and (ii) a new disc instability criterion that triggers bulge and central black hole growth. The model reproduces some fundamental properties of the local galaxy population, such as the fraction of spheroid-dominated galaxies and some scaling relations involving dust. Moreover, the model predicts a galactic dust drop from z ∼ 1 → 0, which becomes closer to the observed one when adopting the new treatment of disc instabilities. This result is related to the newly implemented supermassive black hole growth during disc instabilities, which enhances the quenching of massive galaxies. Consequently, these objects feature a lower gas and dust content. We provide a census of the contribution of all the processes affecting the galactic dust content. Accretion is the dominant dust mass growth process. Destruction by supernovae, astration and ejection by winds have all a non-negligible role in decreasing the overall dust content in galaxies below z ∼ 1. We also discuss predictions concerning extra-galactic dust, confirming that a sputtering efficiency lower than the canonical one is required to match the few available observations. [ABSTRACT FROM AUTHOR]

Radiation is an important contributor to the energetics of the interstellar medium, yet its transport is difficult to solve numerically. We present a novel approach towards solving radiative transfer of diffuse sources via backwards ray tracing. Here, we focus on the radiative transfer of infrared radiation and the radiation pressure on dust. The new module, TreeRay/RadPressure , is an extension to the novel radiative transfer method TreeRay implemented in the grid-based Magneto-Hydrodynamics code Flash. In TreeRay/RadPressure , every cell and every star particle is a source of infrared radiation. We also describe how gas, dust, and radiation are coupled via a chemical network. This allows us to compute the local dust temperature in thermal equilibrium, leading to a significantly improvement over the classical grey approximation. In several tests, we demonstrate that the scheme produces the correct radiative intensities as well as the correct momentum input by radiation pressure. Subsequently, we apply our new scheme to model massive star formation from a collapsing, turbulent core of 150 M⊙. We include the effects of both, ionizing and infrared radiation on the dynamics of the core. We find that the newborn massive star prevents fragmentation in its proximity due to radiative heating. Over time, dust and radiation temperature equalize, while the gas temperature can be either warmer due to shock heating or colder due to insufficient dust–gas coupling. Compared to gravity, the effects of radiation pressure are insignificant for the stellar mass on the simulated time-scale in this work. [ABSTRACT FROM AUTHOR]

This Opinion article begins with a review of important advances in the science of the Mesosphere and Lower Thermosphere (MLT) region of the atmosphere that have occurred over the past two decades since the founding of Atmospheric Chemistry and Physics. The emphasis is on chemistry (although, of course, this cannot be decoupled from discussion of atmospheric physics and dynamics), and the primary focus is on work during the past 10 years. Topics that are covered include: observations (satellite, rocket and ground-based techniques); the variability and connectedness of the MLT on various length- and time-scales; airglow emissions; the cosmic dust input and meteoric metal layers; and noctilucent (or polar mesospheric) ice clouds. The paper then concludes with a discussion of important unanswered questions and likely future directions for the field over the next decade. [ABSTRACT FROM AUTHOR]

The cosmic dust particles found in space are mainly porous aggregates of smaller grains. Theoretically, these aggregates are replicated using fractal geometry, assuming a cluster of spheres. Although the light scattering response of cosmic dust aggregates has been thoroughly studied using clusters of spherical grains in the past few decades, the effect of irregularities on the surface of each grain in an entire aggregate has mostly been neglected. We introduce, for the first time, a visually realistic cosmic dust model that incorporates a mixture of rough fractal aggregates (RFA) and agglomerated debris (Solids) to replicate the unusual polarization–phase curve observed in the case of the interstellar comet 2I/Borisov at multiple wavelengths. The authenticity of the RFA structures has been verified by replicating light scattering results of circumstellar dust analogs from the Granada Amsterdam Light Scattering Database. We demonstrate that the light scattering response from the RFA structures has a very close resemblance to the experimental values. Finally, we model the observed polarization–phase curve of the interstellar comet 2I/Borisov using a mixture of RFA and solid particles. The best-fit data indicate the presence of a higher percentage of porous RFA structures (80%) owing to the fact that the comet carries a higher percentage of small and highly porous pristine cosmic dust particles. Further, the model indicates that the unusually steep polarimetric slope and the high dust-to-gas ratio in newer comets are mainly due to a higher porous-to-compact ratio. [ABSTRACT FROM AUTHOR]

Results from the Cassini‐Huygens space mission at Enceladus revealed a substantial inventory of organic species embedded in plume and E ring ice grains originating from a global subsurface and putative habitable ocean. Compositional analysis by the Cosmic Dust Analyzer indicated the presence of aromatic species and constrained some structural features, although their exact nature remains unclear. As indicated by many studies, among other organic species, low‐mass aromatics likely played a role in the emergence of life on Earth and may be linked to potential prebiotic or biogenic chemistry on icy moons. Here, we study the behavior of single‐ringed aromatic compounds—benzoic acid and two isomeric derivatives, 2,3‐dihydroxybenzoic acid and 2,5‐dihydroxybenzoic acid—using Laser‐Induced Liquid Beam Ion Desorption (LILBID), an analogue setup to simulate the impact ionization mass spectra of ice grains in space. These compounds share common structural features but also exhibit differences in functional groups and substituent positions. We investigate the fragmentation behavior and spectral appearance of each molecule over three simulated impact velocities, in both positive and negative ion modes. Parent compounds can be distinguished easily from their derivatives due to various spectral differences, including the (de)protonated molecular ion peaks appearing at different m/z values. We conclude that distinction between structural isomers in LILBID is more challenging, but some insights can be revealed by considering intermolecular bonding regimes. This work will guide future investigations into elucidating the composition of isomeric biosignatures in ice grains, relevant for future space missions to Enceladus and Europa. Plain Language Summary: The Cassini‐Huygens space mission discovered a plume at Enceladus that ejects gases and frozen ice grains originating from an ocean of liquid water below its icy shell. In these ice grains, a range of interesting organic molecules were discovered by Cassini's Cosmic Dust Analyzer mass spectrometer. Organic molecules are important in the search for life beyond Earth as they form the basis of all known Earth life, and active biology elsewhere would likely have a discernible effect on the local inventory of organic species. One class of organic, with a ring structure of carbon atoms, called aromatics, were discovered in the plume. We investigate the spectral appearance of one example of aromatic compound, benzoic acid, as well as two similar compounds with additional chemical groups attached to the aromatic ring. The two similar compounds have the same mass and general structure, but slightly different arrangements of the additional groups, known as isomers. We find that it is simple to distinguish mass spectral features between benzoic acid and its related compounds, but more difficult to explain the differences between the isomers. This work will assist the analysis of mass spectrometry data from future habitability‐investigating space missions to ocean‐bearing icy moons. Key Points: Cassini revealed a variety of organic compounds including clear evidence of aromatics in the plume of EnceladusIdentifying mass spectral features of isomeric organics enhances our ability to assess the astrobiological potential of Enceladus/EuropaParent aromatic compounds can be easily distinguished from their derivatives in ice grains with impact ionization mass spectrometry [ABSTRACT FROM AUTHOR]

[Display omitted] • An alternative scenario of the evolution of the Universe is proposed. • The absorption of light by cosmic dust causes opacity that counterbalances gravitational forces. • The theory predicts cyclic model of the expansion and contraction of the Universe. • The maximum redshift of the Universe is about 15–17. • The proposed model removes some tensions of the standard cosmological model. Recent observations indicate that the Universe is not transparent but partially opaque due to absorption of light by ambient cosmic dust. This implies that the current cosmological model valid for the transparent universe must be modified for the opaque universe. The paper studies a scenario of the evolution of the Universe when the cosmic opacity steeply rises with redshift, because the volume of the Universe was smaller and the cosmic dust density was higher in the previous epochs. In this case, the light-matter interactions become important, because cosmic opacity produces radiation pressure that counterbalances gravitational forces. The radiation pressure due to cosmic opacity is evaluated and incorporated into the Friedmann equations, which describe cosmic dynamics. The equations are based on the conformal FLRW metric and are consistent with observations of the cosmological redshift as well as time dilation. Using astronomical observations of basic cosmological parameters, the solution of the modified Friedmann equations is numerically modelled. The presented model predicts a cyclic expansion/contraction evolution of the Universe within a limited range of scale factors with no Big Bang. The redshift of the Universe with the minimum volume is about 15–17. The model avoids dark energy and removes several fundamental tensions of the standard cosmological model. In agreement with observations, the modified Friedmann equations predict the existence of very old mature galaxies at high redshifts and they do not limit the age of stars in the Universe. The new model is consistent with theory of cosmic microwave background as thermal radiation of cosmic dust. The paper demonstrates that considering light-matter interactions in cosmic dynamics is crucial and can lead to new cosmological models essentially different from the currently accepted ΛCDM model. [ABSTRACT FROM AUTHOR]

The Cretaceous–Paleogene (K‐Pg) boundary represents the extinction of ~70% of species, a prominent Chicxulub impact event and Deccan volcanism. This work reports the first attempt to extract the micrometeorites (MMs) from the Deccan intertrappean horizons. Eighty‐one spherical particles were studied for their morphological, textural, and chemical characteristics. Intact cosmic spherules with ferromagnesian silicates (6) and Fe‐Ni oxide (7) compositions correspond to MMs from the deep sea and Antarctica. Silicate and Fe‐Ni spherules in this study showcase remarkable preservation, a testament to the highly favorable conditions present. Fe spherules (38) with iron oxide compositions exhibit diagenetic alteration during preservation. Textural analysis of 30 Fe spherules reveals a dendritic, interlocking pattern and slightly elevated Mn content, suggesting these may be fossilized I‐type MMs. However, eight Fe spherules with blocky and cubical granular textures resemble oxidized pyrite spherules. Al‐Fe‐Si spherules (30) possess a significant enrichment of Al and Si within their Fe‐oxide‐dominated composition. Group‐I Al‐Fe‐Si spherules (15) display zoned Al‐Fe‐Si oxide composition, dendritic Mg‐Cr spinel grains, and aerodynamic features, all indicative of impact spherules. The finding of these impact spherules from sampled Deccan intertrappean layer raises the possibility that these paleosols were deposited during the Chicxulub impact event, the only identified impact event with global distribution during the Deccan volcanism time frame. This unique location provides an opportunity for the simultaneous collection of well‐preserved MMs, impact, and volcanic spherules. The exceptional preservation of the studied MMs is likely due to a combination of non‐marine environments, atypical climatic conditions, and rapid deposition. This study further investigates the potential role of cosmic dust flux in the K‐Pg extinction event. We propose that the enhanced cosmic dust flux, a likely scenario during the K‐Pg boundary period, synergistically mixing with impact dust in the upper atmosphere, may have intensified and extended the harsh climatic conditions at the K‐Pg boundary. Subsequently, the deposition of this dust, enriched in bioavailable iron, on Earth's surface might have contributed to the swift recovery of life and environmental conditions. [ABSTRACT FROM AUTHOR]

Michael Ewing Zolensky has been awarded the Leonard Medal for his significant contributions to the field of meteoritics and allied fields. He is an expert in the mineralogy, petrology, and geochemistry of meteoritic materials, and has conducted research on samples collected from asteroids, comets, and cosmic dust. Zolensky has also played a crucial role in the curation and analysis of extraterrestrial samples, and has been involved in organized searches for meteorites and tektites on multiple continents. His work on aqueous alteration and fluid inclusions in meteorites has provided valuable insights into the early solar system. [Extracted from the article]

Dust emission from high-redshift galaxies gives us a clue to the origin and evolution of dust in the early Universe. Previous studies have shown that different sources of dust (stellar dust production and dust growth in dense clouds) predict different ultraviolet (UV) extinction curves for galaxies at z ∼ 7 but that the observed attenuation curves depend strongly on the geometry of dust and star distributions. Thus, we perform radiative transfer calculations under the dust–star geometries computed by a cosmological hydrodynamic simulation (IllustrisTNG). This serves to investigate the dust attenuation curves predicted from 'realistic' geometries. We choose objects with stellar mass and star formation rate appropriate for Lyman break galaxies at z ∼ 7. We find that the attenuation curves are very different from the original extinction curves in most of the galaxies. This makes it difficult to constrain the dominant dust sources from the observed attenuation curves. We further include infrared dust emission in the analysis and plot the infrared excess (IRX)–UV spectral slope (β) diagram. We find that different sources of dust cause different IRX– β relations for the simulated galaxies. In particular, if dust growth is the main source of dust, a variation of dust-to-metal ratio causes a more extended sequence with smaller IRX in the IRX– β diagram. Thus, the comprehensive analysis of the abundance of dust and metals, the UV slope, and the dust emission could provide a clue to the dominant dust sources in the Universe. [ABSTRACT FROM AUTHOR]