EXOA4
Understanding how the planetary environment has influenced the evolution of life and how biological processes have changed the environment is an essential part of any study of the origin and search for signs of life. A central issue in the research on the emergence of life is the paradoxical role of water in pre-biotic chemistry. In fact,on the one hand, water is essential for all known life, on the other hand it is highly destructive for key biomolecules such as nucleic and polypeptides. Earth analogues experiments/instruments test and/or simulation campaigns and limits of life studies are included as well as one of the main topics of this session.
Major Space Agencies identified planetary habitability and the search for evidence of life as a key component of their scientific missions in the next two decades. The development of instrumentation and technology to support the search for complex organic molecules/sings of life/biosignatures and the endurance of life in space environments is critical to define unambiguous approaches to life detection over a broad range of planetary environments. A truly interdisciplinary approach is needed to delve into the core of the issue of emergence of life, because in addition to physics and chemistry it is also need to deploy a number of other sciences. We rely on contribution coming from mathematical or philosophical perspectives not only on astrobiology moreover we think that a part of the answers may lie in scientists who working on cancer research, genetics, space exploration paleontology who are not necessarily involved in this field.
Session assets
INTRODUCTION
The chemistry of life on Earth is based on a basic asymmetry of certain molecules whose threedimensional geometrical structure or conformation is not identical to that of their mirror image, or spatial reflection through a mirror. Parity P, or space inversion, a discrete spatial symmetry transformation of fundamental physics, is broken at the molecular level. Such molecules are said to possess chirality or handedness. The mirror image structures of a chiral molecule are called enantiomers. Homochirality is ubiquitous in biological chemistry from its very start. Amino acids, the building blocks of proteins, and the sugar backbones present in DNA and RNA, are chiral molecules. The origin of biological homochirality has intrigued the scientific community ever since its initial discovery by Pasteur. To unravel its possible origin, we have conducted a combined theoretical and numerical study on the physics of fluid flows in curved pipes. In such coiled ducts, hydrodynamic flows develop a net chirality which can then be transmitted, via viscous shear forces, to the level of molecular self-assembly. This establishes a purely fluid-mechanical mechanism of mirror symmetry breaking from the fluid flow to the constituent molecules [1].
CHIRAL SYMMETRY BREAKING IN HELICAL FLOWS
Let us consider a set of curved pipes with circular section of radius r and radius of curvature R. In order to avoid dimensional bias, dimensionless quantities are considered for the definition of the flow regime: curvature=r/R, pitch=h/R, Re=rρU/μ (Reynolds number) and De=Re√(r/R) (Dean number), where ρ is the density of the fluid, μ the dynamic viscosity, U the flow velocity in the pipe’s centerline direction and h the length of the helical pitch. In the case of toroidal pipes (pitch=0), the cross-sectional secondary flow consists of two symmetric recirculating regions.
However, when the pipe is subjected to a pitch, i.e. in the case of helical pipes, an asymmetric vortex pair structure is generated. This hydrodynamic shear flow asymmetry might then induce chiral symmetry breaking at the molecular level (top-down chirality transfer).
To quantify the symmetry breaking of the cross-sectional vortex pair in helical pipes, a set of numerical tests is carried out [2]. The input consists of the physical flow conditions: Reynolds number, Re, which accounts for the main flow velocity and fluid properties (density and viscosity) along with the geometric properties (curvature, r/R, and pitch, h/R).
When the pipe is subjected to a pitch, i.e. in the case of helical pipes, an asymmetric vortex pair structure is generated. This hydrodynamic shear flow asymmetry might then induce chiral symmetry breaking at the molecular level (top-down chirality transfer).
MODEL RESULTS
The model presented allows the quantification of the chiral symmetry breaking in a helical flow reactor by means of the chiral parameter, χ = χ(De, pitch), given by the following mathematical expression:
where a and b are functions of the dimensionless helical pitch=h/R:
These results are extremely useful to determine the geometric characteristics and operating conditions for the design of an experimental helical flow reactor, in order to control the net chirality of the outflow, leading to numerous important applications in both basic and applied science [4,5], and in origin-of-life scenarios under the influence of fluid flow [6].
REFERENCES
[1] Ribó et al., Science, 292 (5524): 2063-2066 (2001)
[2] Herreros and Hochberg, Physics of Fluids, 35: 043614 (2023)
[3] Herreros and Ligüérzana, Physics of Fluids, 32: 123311 (2020)
[4] Sevim et al., Nat. Commun., 13: 1766 (2022)
[5] Sun et al., Nat. Commun., 9: 2599 (2018)
[6] Brandenburg and Hochberg, Orig. Life Evol. Biosph. 52: 1–2 (2022)
ACKNOWLEDGEMENTS
This research has been funded by grant No. PID2020-116846GB-C22 by the Spanish Ministry of Science and Innovation/State Agency of Research MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. Thanks to Josep M. Ribó for many insightful discussions. I.H. would like to express her gratitude for the years of scientific collaboration with the late David Hochberg, who is deeply mourned by family, friends, and colleagues.
How to cite: Herreros, I. and Hochberg, D.: Chiral vortices in fluids and spontaneous mirror symmetry breaking, Europlanet Science Congress 2024, Berlin, Germany, 8–13 Sep 2024, EPSC2024-205, https://doi.org/10.5194/epsc2024-205, 2024.
Introduction: The recently discovered super-Earth planet Gl 514 b, orbiting the nearby (7.6 pc, [1]) M-dwarf, is an interesting case to explore the habitability of planets that radically differ from the Earth. Habitability studies often rely on the classic definition of the Habitable Zone (HZ), and in particular on the so-called Conservative Habitable Zone (CHZ, [2]). Due to the combination of its relatively large semi-major axis (a=0.42 AU) and eccentricity (e=0.45), Gl 514b lies part of the time inside the CHZ (about 34% of the orbital period) and the rest of the time beyond the outer edge of the CHZ. This suggests the presence of strong seasonal variations that impact the actual habitability of the planet. Tracking the seasonal evolution of habitability is not possible using the HZ approach and requires the application of seasonal climate models tailored for specific stellar, orbital and planetary parameters.
Investigating the potential climates of planets that exhibit seasonal episodes of habitability is intriguing because it could provide insights into the dynamic nature of planetary systems and the potential for the support of life in exotic scenarios. In this sense, the study of the habitability of Gl 514 b can be generalized to all that cases in which there are strong instellation variations, thus helping to define a “Seasonal Habitable Zone”.
The Model: In our study we use the climate model, EOS-ESTM [3,4] for exploring the habitability of Gl 514 b by calculating an index of surface habitability based on the surface temperature distribution. In practice, we explore the habitability as a function of climate factors currently unconstrained by the observations (e.g., Fig 1), such as the ocean cover fraction, the obliquity, and the atmospheric composition. We consider three different types of atmospheres: (i) CO2-dominated, (ii) CO2 + 0.1% CH4 and (iii) CO2 + 1.0% CH4.
Since transits of Gl 514 b have not been detected so far, we estimate the radius and the surface gravity from interior structure models (e.g. [5]) and from the measurements of the minimum mass (5.2 M⊕). The high eccentricity of Gl 514 b suggests that the system is dynamically young and that spin-orbit tidal synchronization may not have yet occurred (e.g. [6]). Assuming that the planet is not tidally locked, in this contribution we present results obtained for a rotation of 1 day (see full paper for complete set of tests).
Results: In the present work, we show how the habitability of Gl 514b is impacted by different combinations of planetary, orbital and atmospheric parameters. The impact of the ocean cover fraction is significant due to the orbit of Gl 514 b (see Figure 1). In fact, the large thermal capacity of even a 25-m shallow ocean provides sufficient thermal inertia to avoid freezing conditions near apoastron. Similarly, the obliquity plays a fundamental role in seasonal habitable events. The higher the obliquity of the planet, the greater the thermal excursion to the poles is (see Figure 2). Nonetheless, we show that these effects are regulated by the total surface pressure and the content of methane in the atmosphere. We present results of the parameter space that allows conditions of continuous and transient habitability.
Figure 1. Predicted values of the habitability index, ℎ, as a function of the ocean cover fraction and total surface pressure for three different atmospheric
compositions. Left panel: CO2-dominated; middle panel: CO2+ 0.1% CH4; right panel: CO2+ 1% CH4. For the remaining parameters we adopt 𝜖 =23.44◦,
𝑃𝑟𝑜𝑡 =1 day and 𝜔𝑝𝑒𝑟𝑖 =0◦. The dashed areas indicate the parameter space in which atmospheric CO2 condensates.
Figure 2. Seasonal and latitudinal maps of surface temperature obtained by extracting the results of Fig. 9c (case with 1% CH4) at constant values of axis obliquity (from left to right: 𝜖 = 20◦ , 30◦ , 40◦ , 50◦, and 60◦) and total pressure (from top to bottom: 𝑝𝑡𝑜𝑡 =5 464, 3 593, 2 782, 2 154, and 1 668 mbar). The solid line indicate the limit within which water can be maintained in liquid form.
Further investigations will include the impact of the host star on the exoplanet environment, especially concerning the photochemical reactions in the atmosphere driven by the large UV flux of the parent star. Apart from the direct impact on habitability due to its ionizing effects, the radiation environment of Gl 514 b may be conductive to the presence of high-altitude organic hazes that directly affect the climate state of the planet.
References:
[1] Damasso M., et al., 2022, A&A, 666, A187.
[2] Kopparapu R. K., et al., 2013, ApJ, 765, 131.
[3] Simonetti P., et al., 2022, ApJ, 925, 105.
[4] Biasiotti L., et al., 2022, MNRAS, 514, 5105.
[5] Fortney J. J., Marley M. S., Barnes J. W., 2007, ApJ, 659, 1661.
[6] Barnes R., 2017, Celestial Mechanics and Dynamical Astronomy, 129, 509.
[7] Damasso M., Nardiello D., 2022, Research Notes of the American Astronomical Society, 6, 184
How to cite: Biasiotti, L., Simonetti, P., Vladilo, G., Ivanovski, S., Damasso, M., Sozzetti, A., and Monai, S.: Potential climate and habitability of Gl 514 b, Europlanet Science Congress 2024, Berlin, Germany, 8–13 Sep 2024, EPSC2024-393, https://doi.org/10.5194/epsc2024-393, 2024.
The Martian surface and shallow subsurface lack stable liquid water, but hygroscopic salts in the regolith, including perchlorates and chlorates, can enable the transient formation of liquid brines. Hygroscopic salts such as perchlorates have been detected on Mars1, and the presence of chlorate salts is highly likely, as indicated by the detection of chlorate in the Martian meteorite EETA790012. Chlorate salts may be even more widespread on Mars, as recent experimental research suggests that under the hyperarid climate and the abundance of iron (hydro)oxide on Mars, chloride oxidation should yield significantly more chlorate than perchlorate3. Additionally, aqueous solutions on Mars may be more likely to be formed by chlorates than perchlorates, highlighting their importance for the habitability of Mars4. Perchlorate and chlorate salts can form liquid brines through a process called deliquescence, where the hygroscopic salt attracts water from the atmosphere to dissolve itself, or through the contact of these salts with water ice. In the shallow subsurface, a thin regolith layer can prevent water ice sublimation, allowing such liquid brines to persist for extended periods. Additionally, regolith layers can shield hypothetical microbes from harmful UV radiation, making the shallow subsurface a promising potential habitat for putative microbial life on Mars.
In this study, we investigated how the combined effects of (per)chlorate salts, UV irradiation, water scarcity, and regolith depth impact microbial survival under simulated Mars-like conditions. While previous studies have examined the effects of perchlorate-containing regolith and UV shielding on microorganisms, none have tested the impact of chlorate salts and regolith depths of multiple centimeters. Our Mars simulation experiments, conducted in the Mars Environmental Simulation Chamber (MESCH), described in detail by Jensen et al.5, uniquely allows for the simultaneous testing of increased salt stress due to water freezing at subzero temperatures and sublimation-induced desiccation at various sample depths. This is enabled by large sample tubes that accommodate regolith depths of up to 15 cm.
We exposed vegetative cells of Debaryomyces hansenii and Planococcus halocryophilus, and spores of Aspergillus niger, to simulated Martian environmental conditions (constant temperatures of about -11°C, low pressure of approximately 6 mbar, a CO2 atmosphere, and 2 hours of daily UV irradiation). Colony Forming Units (CFU) and water content were evaluated at three regolith depths (0-0.5 cm, 1-3 cm, 10-12 cm) before and after 3- and 7-day exposure periods. Each organism was tested under three conditions, where Mars regolith simulant was inoculated with cell suspensions of the three model organisms containing either: 1) 0.5 mol/kg NaClO3, 2) 0.5 mol/kg NaClO4, or 3) no additional salt. These conditions will, in the following sections, be referred to as NaClO3, NaClO4, and salt-free samples, respectively. In addition to the samples exposed to simulated Mars-like conditions, control samples of each organism, prepared in the same way as the exposure samples, were incubated for the same periods at -15°C in a freezer under normal Earth atmospheric conditions.
Our results showed that residual water content increased with depth in all three exposure experiments and for all three tested conditions. Remarkably, as illustrated in Figure 1, the survival rates of the organisms also increased with regolith depth in the NaClO3 and salt-free samples. However, survival rates in the NaClO4 samples were consistently lower across all depths, with the most significant difference observed at 10-12 cm, the depth with the highest residual water content. The proposed reason for this is the emergence of higher salt concentrations in the NaClO3 and NaClO4 samples due to the freezing of water retained in the regolith. This likely resembles realistic changes in brine concentrations in the Martian shallow subsurface. The higher survival rates in chlorate samples indicate that, for these organisms, perchlorate brines are more toxic than chlorate brines under the experimental conditions.Interestingly, in the NaClO4 samples, survival was higher at shallower depths. This can be linked to the shorter brine stability window at lower depths. Faster desiccation at lower depths prevents brines from persisting for long durations, minimizing the time salt stress is exerted on the organisms.
These findings, combined with the potential widespread occurrence of chlorate salts on Mars and their higher likelihood of forming liquid brines, highlight the need for further research on this oxychlorine species. Environments enriched with chlorate salts could be more habitable and should be considered in the search for microbial life on Mars, as most research has focused on the more toxic perchlorate salt.
Figure 1: The median of the survival rates of D. hansenii, P. halocryophilus, A. niger (n=2, SE), and the mean survival rate (dashed line) of the three organisms after (a) a 3-day and (b) a 7-day exposure in the MESCH. The survival rates are displayed for three sample depths, as well as for the control incubated at -15°C in the freezer, in three tested conditions: NaClO3, NaClO4, and salt-free.
References:
1. Hecht, M. H. et al. Detection of Perchlorate and the Soluble Chemistry of Martian Soil at the Phoenix Lander Site. Science (80-. ). 325, 64–67 (2009).
2. Kounaves, S. P., Carrier, B. L., O’Neil, G. D., Stroble, S. T. & Claire, M. W. Evidence of martian perchlorate, chlorate, and nitrate in Mars meteorite EETA79001: Implications for oxidants and organics. Icarus 229, 206–213 (2014).
3. Qu, S.-Y. et al. Preferential Formation of Chlorate over Perchlorate on Mars Controlled by Iron Mineralogy. Nat. Astron. 6, 436–441 (2022).
4. Toner, J. D. & Catling, D. C. Chlorate brines on Mars: Implications for the occurrence of liquid water and deliquescence. Earth Planet. Sci. Lett. 497, 161–168 (2018).
5. Jensen, L. L. et al. A Facility for Long-Term Mars Simulation Experiments: The Mars Environmental Simulation Chamber (MESCH). Astrobiology 8, 537–548 (2008).
How to cite: Fischer, F. C., Schulze-Makuch, D., and Heinz, J.: Habitability of the Martian Shallow Subsurface: Microbial Preference for Chlorate Over Perchlorate under Mars-like Conditions, Europlanet Science Congress 2024, Berlin, Germany, 8–13 Sep 2024, EPSC2024-776, https://doi.org/10.5194/epsc2024-776, 2024.
The formation of methane in Gale Crater remains an intriguing problem due to its sporadic detection and the need to understand its formation and degradation mechanism. Its origin could be biological or inorganic, associated with catalysis facilitated by mineral formations such as serpentines. However, the search for its degradation products, which could remain metastable in the sediments, such as oxalate or acetate, has yet to yield precise results.
The Viking Lander's thermal analyses showed that, although the pyrolysis products generated CO₂ in quantities and intervals compatible with the degradation of organic matter, oxalates should contribute CO2 and CO. At the same time, acetates would likely evolve a mixture of CO2, acetone, and acetic acid. In the case of the CO2 detections by the twin Viking Landers, a lack of indigenous acetone and acetic acid led to rule out the presence of acetates [1].
Subsequent studies [2] discovered that mixing with perchlorate may scrub the acetone and acetic acid evolved by Martian acetates. They demonstrated that this step is not strictly necessary, as thermal decomposition in the presence of oxidants such as perchlorate or peroxide can follow a pattern that generates methane or chloromethane, so the organic origin of CO₂ could not be completely ruled out. The detection limits for acetone were also extremely high for some of the Viking experiments [3]. In addition, chloromethanes were present in Viking data, and the interactions between perchlorates and acetates during heating shifted the perchlorate O2 peaks to lower temperatures, which resulted in better fits with many SAM O2 releases. However, pyrolysis studies are not conclusive.
In addition to SAM, MSL's analytical capabilities include X-ray diffraction (XRD) via the Chemistry and Mineralogy (CheMin) instrument, enabling the identification and quantification of minerals. Another possibility is the determination of these organic compounds as crystalline solid phases using the CheMin diffractometer, which requires intermediate species such as oxalate or acetate to be present in amounts above the 1-2 wt—% detection limit of this instrument [2]. However, so far, the presence of these salts based on the direct determination of their lattice spacings has yet to be observed.
One aspect worth considering is the possibility of methane or its decomposition products, mainly acetate, to be intercalated in the amorphous component or poorly crystalline phases, such as imogolite or halloysite, obtained by recrystallization of aluminosilicates. Exploring this hypothesis could open new avenues for better understanding the formation and persistence of methane on Mars, considering that these compounds could be trapped in amorphous or poorly crystallized mineral matrices, making their direct detection by current methods difficult. Additionally, the possible intercalation of small amounts of these salts in amorphous silicates makes detection via XRD based on the characteristic peaks of the pure crystalline phase very unlikely. However, it opens another detection possibility: the intercalation of compounds such as acetates in these mineral phases produces characteristic and irreversible modifications of the diffraction peaks in the inorganic phase where the intercalation occurs.
To study this possibility, we analyzed the formation of microscopic precursor layers of clay minerals from the nanostructural scale using HREM and SAED as an analog of the formation of secondary minerals through silicate weathering under anoxic conditions. As laboratory analogs of amorphous silicates, we used microtubular structures known as silica-garden that allow the rapid mixing of Si-Al-Fe-Mg-K. Previous experiments with hybrid hydroxide-silica gels showed that the mixing process is one of the determining factors leading to the formation of amorphous silicate multi-oxides (i.e., allophane, imogolite, halloysite). Molecular mixing facilitates further evolution toward more ordered clays. We analyzed the formation of microscopic precursor layers of clay minerals from the nanostructural scale using HREM and SAED.
This process provides the intercalation of hydroxide layers and silica. Furthermore, the formation of the silica garden implies the existence of an extreme change in pH between the internal and external walls of the microtubules, affecting the rate of oxidation of Fe+2 as well as the simultaneous polymerization of silica, providing a way to analyze the influence of the stoichiometry between Si-Fe, the pH, and the rate of oxidation on the formation of clay minerals. Results from these experiments show the presence of curved nanostructures with spacings of 7 Å and 10 Å characteristic of tubular aluminosilicates, such as halloysite, with different degrees of hydration.
In a second series of experiments, dehydrated halloysite (7 Å) was mixed with potassium acetate to produce solid-state intercalation by mixing salt and clay. This experiment produced the appearance of characteristic and irreversible peaks in heating-cooling cycles at spacing values of 9.2 Å and 9.6 Å, depending on the degree of mixing in the intercalation process. This procedure suggests that detailed analysis, using quantitative techniques such as the Rietveld method of poorly crystalline silicates, modified characteristically with organic species like acetate, can be an advantageous method for identifying possible degradation products of organic phases, compared to searching for them as independent solid phases, due to their low detection limit.
Figure 1. (a) Low-resolution TEM images showing nanotubular crystals compatible with halloysite. (b) XRD pattern of poorly crystallized halloysite intercalated with K-ac showing a characteristic peak at 9.2 Å.
References
[1] Benner, S. A. et al. 2000. PNAS, 97(6), 2425–2430.
[2] Lewis, J. M. T. et al., 2021. Journal of Geophysical Research: Planets, 126, e2020JE006803.
[3] Biemann, K., et al., 1976. Science, 194(4260), 72–76.
Acknowledgments
This research has been funded by the SOS-Mars (PID2020-119412RJ-I00) from MICINN Spain and the European Research Council CoG 818602.
How to cite: Gago-Duport, L., Losa-Adams, E., F. Bastero, S., G. Fairén, A., and Gil-Lozano, C.: Tracking the structural changes of poorly crystallized aluminosilicates by CheMin: A way to analyze the presence of organics in sediments of Gale Crater (Mars), Europlanet Science Congress 2024, Berlin, Germany, 8–13 Sep 2024, EPSC2024-1378, https://doi.org/10.5194/epsc2024-1378, 2024.
Assembly theory (AT) is a proposed framework for an agnostic biosignature detection method based on the idea that life produces complex objects in abundance1. The complexity assignment for an object is based on the number of required steps to make the object and derived from graph theory. The consideration for the copy number of that object in the specific environment is based on the idea that functional systems selectively produce objects that are favorable for the systems stability or survival.
While the underlying theory of this life detection method is well established, more experimental work is required to prove the theory’s experimental capabilities.
Figure 1: Depiction of the required steps for an agnostic biosignature method for life detection. Development of the idea, laboratory testing and deployment.
Experimental data has been reported from spectroscopy instruments (IR and NMR) as well as mass spectrometry (MS) instruments (direct injection ESI-MS and LC-MS)2-3. While MS is a promising technology and could enable biosignature research, LC-MS is a technique currently not developed for space exploration due to limitations rising from using solvent as analyte carrier due to their weight but also due to problems creating gradient mixtures in micro gravity.
Gas chromatography (GC)-MS is a solution for this problem as no solvent carrier is required and it is a well-established and tested tool for space exploration4-5. It has been deployed in 1968 in the Viking mission, is currently used on Curiosity’s SAM instrument and will be deployed with MOMA on the Rosalind Franklin Rover, with DraMS on Dragonfly and with MASPEX on Europa Clipper6. Because of the amount of experience collected in GC-MS spaceflight and the fact that a higher number of future missions carry this specific instrument, an experimentally tested GC-MS agnostic biosignature method is needed now. We present preliminary results for AT measurements on a GC-Orbitrap-MS. Orbitrap mass spectrometer are widely used for compound identification as they allow for very precise analysis of intact molecules as well as for fragments after additional collision steps. This specific type of MS is currently under development for future lander missions6.
Due to the differences between GC-MS and LC-MS or direct infusion, developing a method for AT calculation required consideration towards several parameters. The noise floor reduction and blank subtraction methods needed to be adjusted for GC-MS. Concentration limits were investigated to understand the AT capabilities of the instrument for the specific analytes. Further the choice of columns (polar/ non-polar) and derivatization methods and their impact on the AT calculation result will be presented. Developing an agnostic biosignature method that can be used on instruments that are already in space collecting data offers new opportunities in biosignature development and interpreting collected data.
References:
1. Sharma, A., Czégel, D., Lachmann, M. et al. Assembly theory explains and quantifies selection and evolution. Nature 622, 321–328 (2023). https://doi.org/10.1038/s41586-023-06600-9
2. Jirasek, M., Sharma, A., Bame, J. R. et al.Investigating and Quantifying Molecular Complexity Using Assembly Theory and Spectroscopy. ACS Central Science (2024). https://doi.org/1021/acscentsci.4c00120
3. Marshall, S.M., Mathis, C., Carrick, E. et al.Identifying molecules as biosignatures with assembly theory and mass spectrometry. Nat Commun 12, 3033 (2021). https://doi.org/10.1038/s41467-021-23258-x
4. Mahaffy, P.R., Webster, C.R., Cabane, M. et al. The Sample Analysis at Mars Investigation and Instrument Suite. Space Sci Rev 170, 401–478 (2012). https://doi.org/10.1007/s11214-012-9879-z
5. Akapo, S. O., Dimandja, J.-M.D., Kojiro, D. R. et al. Gas chromatography in space. Journal of Chromatography A, 843, 1–2, 147-162 (1999).
https://doi.org/10.1016/S0021-9673(98)00947-9
6. Luoth, C., Mahaffy, P., Trainer, M. al. Planetary Mass Spectrometry for Agnostic Life Detection in the Solar System. Frontiers in Astronomy and Space Sciences, 8 (2021). https://doi.org/10.3389/fspas.2021.755100
How to cite: Asche, S., Weiss, G. M., Sequin, F., and Graham, H. V.: Development of a gas chromatography mass spectrometry method for assembly theory measurements, Europlanet Science Congress 2024, Berlin, Germany, 8–13 Sep 2024, EPSC2024-662, https://doi.org/10.5194/epsc2024-662, 2024.