Solar System Bodies Research Articles

Processing and Analysis for Radio Science Experiments (PARSE): Graphical Interface for Bistatic Radar

Abstract Opportunistic bistatic radar (BSR) observations of planetary surfaces can probe the textural and electrical properties of several solar system bodies without needing a dedicated instrument or additional mission requirements, providing unique insights into volatile enrichment and supporting future landing, anchoring, and in situ sampling. Given their opportunistic nature, complex observation geometries, and required radiometric knowledge of the received radio signal, these data are particularly challenging to process, analyze, and interpret for most planetary science data users, who can be unfamiliar with link budget analysis of received echoes. The above impedes real-time use of BSR data to support mission operations, such as identifying safe landing locations on small bodies, as was the case for the Rosetta mission. To address this deficiency, we develop an open-source graphical user interface—Processing and Analysis for Radio Science Experiments (PARSE)—that assesses the feasibility of performing BSR observations and automates radiometric signal processing, power spectral analysis, and visualization of DSN planetary radio science data sets acquired during mission operations or archived on NASA’s Planetary Data System. In this first release, PARSE automates the processing chain developed for Dawn at Asteroid Vesta, streamlining the detection of DSN-received surface-scatter echoes generated as the spacecraft enters/exits occultations behind the target. Future releases will include support for existing Arecibo data sets and other Earth-based radio observatories. Our tool enables the broader planetary science community, beyond planetary radar signal processing experts, to utilize BSR data sets to characterize electrical and textural properties of planetary surfaces. Such tools are becoming increasingly important as the number of space missions—and subsequent opportunities for orbital radio science observations—continue to grow.

ВОПРОСЫ И ПЕРСПЕКТИВЫ ПРЕПОДАВАНИЯ ТЕМЫ «СОЛНЕЧНАЯ СИСТЕМА» ПО УЧЕБНИКАМ АСТРОНОМИИ

The article deals with the issues of teaching the topic "Solar system" of the discipline "Astronomy". The old textbook "Astronomy" by E.P. Levina and new - B.A. Vorontsova–Velyaminova, E.K. Strout and V.M. Charugin - in which the material about the planetary system is borrowed from publications of the last century. At present, what is stated in the textbook by B.A. Vorontsova-Velyaminov and E.K. Strout, the historically established idea of the formation and structure of the solar system (from planets alone) contradicts new discoveries and the observed harmonious structure of the solar system. The erroneousness of assigning the status of "minor planet" to asteroids of the main belt and many objects of the Kuiper belt is substantiated. this leads students to the misconception that there are many planets in the solar system. To the textbook "Astronomy" V.M. Charugin, the author of this article prepared a textbook "The Solar System of the 21st Century", which provides a model of the structure of the entire Solar System and the cometary hypothesis of its origin. The textbook contains a table "Periodic system of celestial bodies of the entire solar system" for astronomy classrooms, similar in significance to the table "Periodic system of chemical elements of D.I. Mendeleev.

Elucidating evolution processes of Solar System bodies: Approaches by mineralogical study of various kinds of extraterrestrial materials

For the past 30 years, I have performed a mineralogical study of various kinds of extraterrestrial materials focusing on evolution processes of Solar System bodies. The samples analyzed range from primitive chondritic materials returned by spacecrafts to differentiated meteorites including Martian and lunar samples. The first of these analyzed meteorites was an angrite, one of the oldest known achondrites, in collaboration with researchers at NASA's Johnson Space Center, USA. I pointed out the importance of olivine xenocrysts by studying many quenched angrites and showed that bulk compositions of quenched angrites were controlled by resorption degrees of these xenocrysts. Soon I became involved in studying Martian meteorites. In my early works, I found that some shergottite Martian meteorites experienced undercooling of magma and represented parent magma compositions by combining crystallization experimental results. I also revealed that nakhlite Martian meteorites had correlated petrography and mineralogy that could be explained by crystallization at different locations (burial depths) in a common cooling cumulate pile. The presence of remarkable shock features (e.g., darkening of olivine) in Martian meteorites is striking, and it appears that prolonged post-shock heating history largely erased the high-pressure polymorphs in many cases. My research deals with primitive solar system materials including Wild 2 cometary particles and Itokawa asteroidal particles. Studying these samples using electron beam and synchrotron radiation analyses has strengthened the interpretations of their origins. Another important tool employed is electron backscatter diffraction (EBSD) analysis. I applied this technique to identify several new minerals such as dmitryivanovite, andreyivanovite, and kushiroite in early 2000s. EBSD was also used to analyze preferred crystallographic orientation of olivine in brachinites, revealing rigorous magmatic and/or rheological activities in the parent body. At present I am analyzing Ryugu samples returned by the Hayabusa2 spacecraft as a preliminary analysis team member, which broadens our understanding of the formation and evolution processes of solid materials in the early Solar System.

Triton Haze Analogs: The Role of Carbon Monoxide in Haze Formation

AbstractTriton is the largest moon of the Neptune system and possesses a thin nitrogen atmosphere with trace amounts of carbon monoxide and methane, making it of similar composition to that of the dwarf planet Pluto. Like Pluto and Saturn's moon Titan, Triton has a haze layer thought to be composed of organics formed through photochemistry. Here, we perform atmospheric chamber experiments of 0.5% CO and 0.2% CH4 in N2 at 90 K and 1 mbar to generate Triton haze analogs. We then characterize the physical and chemical properties of these particles. We measure their production rate, their bulk composition with combustion analysis, their molecular composition with very high resolution mass spectrometry, and their transmission and reflectance from the optical to the near‐infrared with Fourier Transform Infrared (FTIR) Spectroscopy. We compare these properties to existing measurements of Triton's tenuous atmosphere and surface, as well as contextualize these results in view of all the small, hazy, nitrogen‐rich worlds of our solar system. We find that carbon monoxide present at greater mixing ratios than methane in the atmosphere can lead to significantly oxygen‐ and nitrogen‐rich haze materials. These Triton haze analogs have clear observable signatures in their near‐infrared spectra, which may help us differentiate the mechanisms behind haze formation processes across diverse solar system bodies.

Flash LiDAR-Based Super-Resolution Mapping for Small Solar System Body Exploration

Safe spacecraft navigation on small solar system bodies requires an accurate and high-resolution representation of the surface. This work develops a super-resolution mapping algorithm based on flash LiDAR measurements for unstructured terrain. It integrates a novel approach of processing multiple range values per pixel per measurement to increase the measurement redundancy and thus the map accuracy. The proposed algorithm is thus able to overcome the limitations of the low flash LiDAR resolution. Micro- and macro-motion strategies are recommended to guarantee subpixel displacements crucial for the super-resolution algorithm, and measurement constraints are introduced to ensure high measurement quality. Computational experiments based on an advanced Flash LiDAR model in a realistic simulation environment of comet 67P/Churyumov-Gerasimenko compare the resulting digital elevation model (DEM) with a baseline DEM and demonstrate the advantages of our algorithm.

Relative Navigation and Terrain-based Path Planning using Flash LiDAR based Surfel Grid Map for Asteroid Exploration

Due to lack of spacecraft's global position and attitude information on small solar system bodies (SSSBs) like asteroids, only relative state measurements are available for navigation. Therefore, relative navigation with respect to a local reference frame is the basis for in-situ autonomous exploration on the asteroids. The relative navigation changes a local reference frame during the flight, which guarantees local accuracy of state estimation and mapping. We present the relative navigation framework using surfel grid map-based scan-to-map matching for localization and mapping on asteroid surface. We also propose a terrain-based path planning that makes use of inherent terrain surface properties of surfel grid maps. A thorough validation of our navigation approach and comparison to a global flash LiDAR-based navigation in different flight scenarios and in both MIL (model-in-the-loop) and real-time PIL (processor-in-the-loop) tests show the viability of this novel navigation framework.

SOLIS

Context. Isotopic fractionation is an important tool for investigating the chemical history of our Solar System. In particular, the isotopic fraction of nitrogen (14N/15N) is lower in comets and other pristine Solar System bodies with respect to the value measured for the protosolar nebula, suggesting a local chemical enrichment of 15N during the formation of the Solar System. Therefore, interferometric studies of nitrogen fractionation in Solar System precursors are needed for us to obtain clues about our astrochemical origins. Aims. In this work we have investigated the variation in the 14N/15N ratio in one of the closest analogues of the environment in which the Solar System was born: the protocluster OMC-2 FIR4. We present the first comparison at high angular resolution between HCN and N2H+ using interferometric data. Methods. We analysed observations of the HCN isotopologues H13CN and HC15N in the OMC-2 FIR4 protocluster. Specifically, we observed the transitions H13CN (1−0) and HC15N (1−0) with the NOrthern Extended Millimeter Array (NOEMA) within the context of the IRAM Seeds Of Life In Space (SOLIS) Large Program. We combined our results with analysis of archival data obtained with the Atacama Large Millimeter Array of N2H+ and its 15N isotopologues. Results. Our results show a small regional variation in the 14N/15N ratio for HCN, from ~250 to 500. The ratios in the central regions of FIR4, where the candidate protostars are located, are largely consistent with one another and within that range (~300). They also show little variation from the part of the protocluster known to harbour a high cosmic-ray ionisation rate to the portion with a lower rate. We also found a small variation in the 14N/15N ratio of N2H+ across different regions, from ~200 to ~400. Conclusions. These results suggest that local changes in the physical parameters occurring on the small linear scales probed by our observations in the protocluster do not seem to affect the 14N/15N ratio in either HCN or N2H+ and hence that this is independent of the molecule used. Moreover, the high level of irradiation due to cosmic rays does not affect the N fractionation either.

Interstellar Now! Missions to Explore Nearby Interstellar Objects

The recently discovered first high velocity hyperbolic objects passing through the Solar System, 1I/'Oumuamua and 2I/Borisov, have raised the question about near term missions to Interstellar Objects. In situ spacecraft exploration of these objects will allow the direct determination of both their structure and their chemical and isotopic composition, enabling an entirely new way of studying small bodies from outside our solar system. In this paper, we map various Interstellar Object classes to mission types, demonstrating that missions to a range of Interstellar Object classes are feasible, using existing or near-term technology. We describe flyby, rendezvous and sample return missions to interstellar objects, showing various ways to explore these bodies characterizing their surface, dynamics, structure and composition. Interstellar objects likely formed very far from the solar system in both time and space; their direct exploration will constrain their formation and history, situating them within the dynamical and chemical evolution of the Galaxy. These mission types also provide the opportunity to explore solar system bodies and perform measurements in the far outer solar system.

Preliminary analysis of the Hayabusa2 samples returned from C-type asteroid Ryugu

C-type asteroids1 are considered to be primitive small Solar System bodies enriched in water and organics, providing clues to the origin and evolution of the Solar System and the building blocks of life. C-type asteroid 162173 Ryugu has been characterized by remote sensing2–7 and on-asteroid measurements8,9 with Hayabusa2 (ref. 10). However, the ground truth provided by laboratory analysis of returned samples is invaluable to determine the fine properties of asteroids and other planetary bodies. We report preliminary results of analyses on returned samples from Ryugu of the particle size distribution, density and porosity, spectral properties and textural properties, and the results of a search for Ca–Al-rich inclusions (CAIs) and chondrules. The bulk sample mainly consists of rugged and smooth particles of millimetre to submillimetre size, confirming that the physical and chemical properties were not altered during the return from the asteroid. The power index of its size distribution is shallower than that of the surface boulder observed on Ryugu11, indicating differences in the returned Ryugu samples. The average of the estimated bulk densities of Ryugu sample particles is 1,282 ± 231 kg m−3, which is lower than that of meteorites12, suggesting a high microporosity down to the millimetre scale, extending centimetre-scale estimates from thermal measurements5,9. The extremely dark optical to near-infrared reflectance and spectral profile with weak absorptions at 2.7 and 3.4 μm imply a carbonaceous composition with indigenous aqueous alteration, matching the global average of Ryugu3,4 and confirming that the sample is representative of the asteroid. Together with the absence of submillimetre CAIs and chondrules, these features indicate that Ryugu is most similar to CI chondrites but has lower albedo, higher porosity and more fragile characteristics.

The Indeterminacy Bottleneck: Implications for Habitable Worlds

It is often assumed that the transition between chemical evolution and biological evolution undergoes a smooth process; that once life has arisen, it will automatically 'flood' a solar system body. However, there is no a priori reason to assume that a link between them is a given. The fact that both chemical evolution and biological evolution meet in a single point can be critical. Thus, one may ask: can a world's environment be favourable for chemical evolution but not for biological evolution, or vice versa? This is an important question worth exploration because certain worlds in the solar system in the past seemed to possess the possibility of chemical evolution, while several worlds in the present seem to exhibit such a possibility. Have such solar system bodies thus been, or are, 'flooded' by life? Did they possess the opportunity for biological evolution? The answer depends on the very nature of certain conditions under which evolution occurs, which may indicate that a link between chemical evolution and biological evolution is not automatically realised on a habitable solar system body. Thus, these conditions imply that in the emergence and distribution of cellular life, there exists an indeterminacy bottleneck at which chemical evolution and biological evolution meet through a single cell, whose descendants goes 'information explosive', 'entropy implosive' and 'habitat expansive', which determine whether life moves on to new environments. The consequence is that a world's environment can indeed be favourable for biological evolution, but not for chemical evolution. Thus, even if chemical evolution leads to the emergence of a microbial organism in a world, then it is not a given that such a first life form will be subjected to distribution to other environments; and not a given that its existence will continue in the environment it originated in. Thus, the bottleneck may be one of the decisive factors in the differences between habitable and inhabited worlds.

New Evidence for Wet Accretion of Inner Solar System Planetesimals from Meteorites Chelyabinsk and Benenitra

Abstract We investigated the hydrogen isotopic compositions and water contents of pyroxenes in two recent ordinary chondrite falls, namely, Chelyabinsk (2013 fall) and Benenitra (2018 fall), and compared them to three ordinary chondrite Antarctic finds, namely, Graves Nunataks GRA 06179, Larkman Nunatak LAR 12241, and Dominion Range DOM 10035. The pyroxene minerals in Benenitra and Chelyabinsk are hydrated (∼0.018–0.087 wt.% H2O) and show D-poor isotopic signatures (δDSMOW from −444‰ to −49‰). On the contrary, the ordinary chondrite finds exhibit evidence of terrestrial contamination with elevated water contents (∼0.039–0.174 wt.%) and δDSMOW values (from −199‰ to −14‰). We evaluated several small parent-body processes that are likely to alter the measured compositions in Benenitra and Chelyabinsk and inferred that water loss in S-type planetesimals is minimal during thermal metamorphism. Benenitra and Chelyabinsk hydrogen compositions reflect a mixed component of D-poor nebular hydrogen and water from the D-rich mesostases. A total of 45%–95% of water in the minerals characterized by low δDSMOW values was contributed by nebular hydrogen. S-type asteroids dominantly composed of nominally anhydrous minerals can hold 254–518 ppm of water. Addition of a nebular water component to nominally dry inner solar system bodies during accretion suggests a reduced need of volatile delivery to the terrestrial planets during late accretion.

Ironing Out Isotopic Differences Among Rocky Bodies

The variability of iron isotopes among rocky bodies in the inner Solar System provides a window onto the diversity of materials and mechanisms from which they formed. The magnitude of isotopic variation in mantle-derived rocks within a given body is similar to that between different planetary bodies. Isotopic signatures arising from primordial events, namely, evaporation/condensation, core formation and melting/crystallization, may be progressively diluted, modified, and redistributed over time by global recycling processes such as plate tectonics. Here, we assess the relative influence of these primordial mechanisms on the iron isotope compositions of igneous rocks and their implications for the structure and accretion histories of rocky planets.

The Infrared Complex Refractive Index of Amorphous Ammonia Ice at 40 K (1.43–22.73 μm) and Its Relevance to Outer Solar System Bodies

Abstract A near-IR absorption band at 2.2 μm linked to ammonia-containing ice has been detected on icy bodies throughout the solar system and appears in the extensive volume of data for Pluto and Charon returned by New Horizons. This band is an important clue for understanding the abundance of ammonia and ammoniated compounds on the surface of outer solar system bodies and requires new laboratory data for its full analysis. To satisfy this data need, the complex refractive index of amorphous ammonia ice was calculated from experimental infrared transmission spectra with ice deposition and measurements conducted at 40 K, a characteristic surface temperature for outer solar system bodies. The measured imaginary part of the complex refractive index and associated band strength calculations are generally larger than prior published values for amorphous ammonia ice at 30 K. The complex refractive index for amorphous ammonia at 40 K computed in the mid-infrared region (2.5–22.73 μm) will also be valuable for interpreting observations of both solar system and astrophysical sources anticipated with the Near InfraRed Spectrograph and Mid-Infrared Instrument on the James Webb Space Telescope.

Electromagnetic characterization of a crushed L-chondrite for subsurface radar investigations of solar system bodies

Radar sounders are becoming essential methods for the exploration of the Earth, Planets and the interior of small Solar System bodies. The performance of a radar is strongly related to the electromagnetic parameters of the materials composing the body surface and subsurface. Given the very limited access to planetary soil and rocks, meteorites represent important analogues of asteroids and Jovian icy moon crusts. Electromagnetic properties of meteorites are poorly known as they have seldom been investigated through extensive laboratory measurements as a function of frequency, temperature, and density. The present work builds upon a previous study on a solid chondrite sample, extending the measurements to the complex dielectric permittivity and magnetic permeability of a crushed L5 chondrite in the frequency range typical of the radars proposed for future space missions, such as AIDA, JUICE and EUROPA CLIPPER. The results show that for such dry granular materials the main parameter controlling the electromagnetic properties is the sample bulk density. Moreover, our results highlight the importance to account for magnetic properties in radar signal attenuation estimation for planetary exploration.

Lunar-like silicate material forms the Earth quasi-satellite (469219) 2016 HO3 Kamo\u02bboalewa

Little is known about Earth quasi-satellites, a class of near-Earth small solar system bodies that orbit the sun but remain close to the Earth, because they are faint and difficult to observe. Here we use the Large Binocular Telescope (LBT) and the Lowell Discovery Telescope (LDT) to conduct a comprehensive physical characterization of quasi-satellite (469219) Kamoʻoalewa and assess its affinity with other groups of near-Earth objects. We find that (469219) Kamoʻoalewa rotates with a period of 28.3 (+1.8/−1.3) minutes and displays a reddened reflectance spectrum from 0.4–2.2 microns. This spectrum is indicative of a silicate-based composition, but with reddening beyond what is typically seen amongst asteroids in the inner solar system. We compare the spectrum to those of several material analogs and conclude that the best match is with lunar-like silicates. This interpretation implies extensive space weathering and raises the prospect that Kamo’oalewa could comprise lunar material.

Experimental chondrite–water reactions under reducing and low-temperature hydrothermal conditions: Implications for incipient aqueous alteration in planetesimals

The presence of hydrous minerals in carbonaceous chondrites has been considered important evidence for the former presence of liquid water in parent asteroids. However, the evolution of water–rock reactions in hydrous asteroids remains not well constrained. Here, we conduct water–rock type experiments and chemical equilibria calculations under low-temperature hydrothermal and reducing conditions to investigate the alteration process and secondary mineral assemblages of chondritic rock in the earliest alteration stage. Using synthetic chondrite (mixtures of olivine (forsterite95), orthopyroxene (enstatite95), silicate glass, troilite and Femetal) as a starting material, our experiments were conducted at temperatures of 25 °C–80 °C for time periods between 1 and 460 days at a water-to-rock mass ratio of 10. A combination of X-ray diffraction (XRD) and transmission electron microscope (TEM) analyses revealed that the primary secondary phases consisted of pyrrhotite, an amorphous SiO2-rich phase and saponite at 80 °C, while the secondary phase consisted of an amorphous SiO2-rich phase and saponite at 25 °C. At both temperatures, the SiO2-rich phases and saponite densely covered the surface of the primary phases. The Fe/Mg ratios of saponite and amorphous SiO2-rich phases showed clear difference between 80 °C and 25 °C. Saponite that was formed at 80 °C was richer in Fe than the initial silicate phases, and the highest Fe/Mg ratios were obtained in the saponite encrusting the troilite and Femetal. These results suggest that the Fe distributed from the troilite and Femetal induced the formation of Fe-rich saponite. Some of the secondary minerals observed from our alteration experiments were consistent with those expected by chemical equilibria calculations. However, the formation of serpentine, the dominant secondary mineral expected from chemical equilibria calculations, was not observed in our experiments up to 460 days, probably because the preferential dissolution of SiO2-rich silicate glass in the earliest stage of alteration induced the formation of saponite rather than serpentine. The secondary mineral assemblage and its morphological characteristics, as observed by our alteration experiments, showed similarities with carbonaceous chondrites such as CM2 and CO3 chondrites. This alteration might be explained by water–rock reactions at low temperatures and by the short time alteration. These findings better constrain the temperatures and timescales of aqueous alterations in hydrous asteroids, as well as the role of water in the early solar system bodies.

Laser Ablation Ionization Mass Spectrometry: A Space Prototype System for In Situ Sulphur Isotope Fractionation Analysis on Planetary Surfaces

The signatures of element isotope fractionation can be used for the indirect identification of extant or extinct life on planetary surfaces or their moons. Element isotope fractionation signatures are very robust against the harsh environmental conditions, such as temperature or irradiation, which typically prevail on solar system bodies. Sulphur is a key element for life as we know it and bacteria exist, such as sulphur reducing bacteria, that can metabolize sulphur resulting in isotope fractionations of up to −70‰ δ34S. Geochemical processes are observed to fractionate up to values of −20‰ δ34S hence, fractionation exceeding that value might be highly indicative for the presence of life. However, the detection of sulphur element isotope fractionation in situ, under the assumption that life has existed or still does exist, is extremely challenging. To date, no instrument developed for space application showed the necessary detection sensitivity or measurement methodology for such an identification. In this contribution, we report a simple measurement protocol for the accurate detection of sulphur fractionation δ34S using our prototype laser ablation ionization mass spectrometer system designed for in situ space exploration missions. The protocol was elaborated based on measurements of five sulphur containing species that were sampled at different Mars analogue field sites, including two cave systems in Romania and the Río Tinto river environment in Spain. Optimising the laser pulse energy of our laser ablation ionization mass spectrometer (LIMS) allowed the identification of a peak-like trend of the 34S/32S ratio, where the maximum, compared to internal standards, allowed to derive isotope fractionation with an estimated δ34S accuracy of ∼2‰. This accuracy is sufficiently precise to differentiate between abiotic and biotic signatures, of which the latter, induced by, e.g., sulphate-reducing microorganism, may fractionate sulphur isotopes by more than −70‰ δ34S. Our miniature LIMS system, including the discussed measurement protocol, is simple and can be applied for life detection on extra-terrestrial surfaces, e.g., Mars or the icy moons like Europa.

Early solar irradiation as a source of the inner solar system chromium isotopic heterogeneity

AbstractDifferent solar system objects display variable abundances of neutron‐rich isotopes such as 54Cr, 50Ti, and 48Ca, which are commonly attributed to a heterogeneous distribution of presolar grains in different domains of the solar system. Here, we show that the heterogeneity of 54Cr/52Cr and the correlation of 54Cr/52Cr with Fe/Cr in metal fractions of EH3 chondrites and in inner solar system bodies can be attributed to variable irradiation of dust grains by solar energetic particles and variable mixing of irradiated material in the different domains of the inner solar nebula. The isotope variations in inner solar system objects can be generated by ~300 y long local irradiation of mm‐ to cm‐sized solids with average solar energetic particle fluxes of ~105 times the modern value. The relative homogeneity of 53Cr/52Cr in inner solar system objects can be a consequence of the production of 53Mn by the early irradiation of dust, evaporation, and nebula‐wide homogenization of Mn due to high temperatures, followed by Mn/Cr fractionation within the first few million years of the solar system. The 54Cr/52Cr of the Earth can be produced by irradiated pebbles and <15 wt% of CI chondrite like material. Alternatively, Earth may contain only a few % of CI chondrite like material but then must have an Fe/Cr ratio 10–15% higher than CI chondrites.

Sulfur ion irradiation experiments simulating space weathering of Solar System body surfaces

Context. Sulfur (S) is of prime interest in the context of (astro)chemical evolution and habitability. However, the origin of S-bearing organic compounds in the Solar System is still not well constrained. Aims. We carried out laboratory experiments to test whether complex organosulfur compounds can be formed when surfaces of icy Solar System bodies are subject to high-energy S ions. Methods. Non-S-bearing organic residues, formed during the processing of astrophysical H2O:CH3OH:NH3-bearing ice analogs, were irradiated with 105 keV-S7+ ions at 10 K and analyzed by high-resolving FT-ICR-MS. The resulting data were comprehensively analyzed, including network analysis tools. Results. Out of several thousands of detected compounds, 16% contain at least one sulfur atom (organosulfur (CHNOS) compounds), as verified via isotopic fine structures. These residue-related organosulfur compounds are different from those formed during the S ion irradiation of ices at 10 K. Furthermore, insoluble, apolar material was formed during the sulfur irradiation of residues. Potential organosulfur precursors (CHNO molecules) were identified by means of molecular networks. Conclusions. This evidence of organosulfur compounds formed by sulfur irradiation of organic residues sheds new light onto the rich and complex scope of pristine organosulfur chemistry in the Solar System, presented in the context of current and future space missions. These results indicate that the space weathering of Solar System bodies may lead to the formation of organosulfur compounds.

The CoPhyLab comet-simulation chamber.

The Comet Physics Laboratory (CoPhyLab) is an international research program to study the physical properties of cometary analog materials under simulated space conditions. The project is dedicated to studying, with the help of multiple instruments and the different expertise and background from the different partners, the physics of comets, including the processes inside cometary nuclei, the activity leading to the ejection of dust and gas, and the sub-surface and surface evolution of cometary nuclei when exposed to solar illumination. CoPhyLab will provide essential information on the formation and evolution of comets and insights into the origins of primitive Solar System bodies. To this end, we constructed a new laboratory that hosts several small-scale experiments and a large-scale comet-simulation chamber (L-Chamber). This chamber has been designed and constructed to host ice-dust samples with a diameter of up to 250 mm and a variable height between 100 and 300 mm. The cometary-analog samples will be kept at temperatures below 120 K and pressures around 10-6 mbar to ensure cometary-like conditions. In total, 14 different scientific instruments are attached to the L-Chamber to study the temporal evolution of the physical properties of the sample under different insolation conditions. Due to the implementation of a scale inside the L-Chamber that can measure weight changes of the samples with high precision, the cooling system is mechanically decoupled from the sample holder and cooling of the samples occurs by radiation only. The constructed chamber allows us to conduct uninterrupted experiments at low temperatures and pressures up to several weeks.