Research Centre for Astronomy and Earth Sciences

On early Mars, the integration of surface, groundwater, and climate systems into an integrated hydrological system remains poorly understood. The partitioning of precipitation, between surface and groundwater via infiltration, controls the Martian aquifer recharge rates and, subsequently, surface erosion processes. We investigate infiltration at two scales, near‐surface and deep crustal. We estimate infiltration timescales, revealing that near‐surface water loss enhances aeolian erosion over short periods (hours to days). Deep crustal recharge, which requires decades to centuries, affects the deep aquifer response and the water budget. Martian crustal heterogeneity influences infiltration dynamics and runoff production making them dependent on the duration of precipitation. This interaction suggests that the responses of the aquifers to recharge events and groundwater upwelling likely lag behind climate optimum conditions. The accommodation space between topography and aquifer influences Mars' water budget by transiently sequestering water, thus limiting the available water for surface evaporation and inclusion in climate dynamics.

In the past few decades, large universal structures have been found that challenge the homogeneity and isotropy expected in standard cosmological models. The largest of these, identified as the Hercules–Corona Borealis Great Wall, was found in 2014 in the northern galactic hemisphere in the redshift range of 1.6≤z≤2.1. Subsequent studies used an increasing gamma-ray burst database to show that the cluster was unlikely to have been caused by statistical sampling uncertainties. This study re-examines burst clustering in the northern galactic hemisphere using a recently developed methodology. Evidence is provided that the Hercules–Corona Borealis Great Wall cluster is larger than previously thought, with members potentially spanning the redshift range of 0.33≤z≤2.43. The extension of this cluster’s size does not appear to have been due to statistical variations or sampling biases.

This Eur. Phys. J. A volume 58 is dedicated to the life and work of Dr. Franz Käppeler from Karlsruhe Institute for Technology (KIT) who died on 20 November 2021, after a short illness. He was one of the leading experimentalists in the field of experimental nuclear astrophysics in Germany and worldwide for decades. Many of the authors of this volume knew Franz personally and many others were directly or indirectly inspired by his work and personality. All references in this introductory article refer to publications in this volume, not necessary to actual work by Dr. Käppeler.

So far, published geochronological data poorly constrain the Late Pleistocene glacial fluctuations in the Făgăraş Mts (Southern Carpathians, Romania). The deglaciation chronology in the central Făgăraş Mts is supported by new (n = 5) and recalculated (n = 5) ¹⁰Be exposure ages from a southern and two northern valleys. Cosmic ray exposure (CRE) ages were calculated considering the effects of surface denudation, uplift and snow-shielding. A ¹⁰Be exposure age obtained from a glacial landform representing the last glacierets of the central Făgăraş Mts yielded an age of 13.3 ± 1.2 ka. A polished bedrock sample and a moraine boulder constrain the age of a cirque glacier stage to 14.5 ± 1.5 ka, while quite coherent CRE ages from two erratic boulders place the previous stage at ~18.7 ka (18.6 ± 1.7 ka and 18.7 ± 1.7 ka). These glacial stages coincide with major deglaciation stages M4 and M2a reconstructed in the Retezat Mts, derived from comparable CRE ages calculated using the same methodology; however, geomorphological and/or geochronological evidence of the intermediate stages is still not found in the central Făgăraş Mts. All CRE ages gathered from the landforms corresponding to the more extended glacial stages are younger than expected from their morphostratigraphic position and thus considered as minimum age constraints. However, considering the coherent CRE ages of the above morphostratigraphic stage, it is likely that the balanced-budget glaciological conditions corresponding to these more extended stages prevailed before ~19 ka and likely coincided with the cold peaks of the Marine Isotope Stage 2. The currently available in situ ¹⁰Be data do not support the existence of a period of glacier advance during the Holocene or Greenland Stadial-1 (Younger Dryas) in the central Făgăraş Mts.

Knowledge of the formation temperatures of geological deposits is essential for investigating their genesis. Oxygen isotope thermometry (OIT), using the temperature dependence of oxygen isotope fractionation between host carbonate mineral and mineral-forming water trapped in fluid inclusions, and clumped isotope thermometry, based on the degree of ¹³C and ¹⁸O clumping, are receiving increasing interest. However, only a few studies have applied combinations of these methods, and their databases are limited. In this study, we compare OIT and clumped isotope temperatures obtained for 18 samples from Mesozoic to early Cenozoic calcite veins. Our analysis indicates that the formation temperatures were preserved in the clumped isotopic compositions (16–45 °C), whereas the OIT temperatures were shifted to lower temperatures (− 2 to 33 °C). An OIT temperature shift occurred, due to a retrograde oxygen isotope exchange between the fluid inclusion water and the host calcite. These results imply that the retrograde isotope exchange should be taken into consideration, even for low-temperature carbonate deposits, if a sufficiently long time is available.

Urban sprawl and brownfields are recognized as the main challenges for sustainable land use in post-industrial cities. Using a mixed methodology (GIS and interviews), this research aimed to examine the relationship between the redevelopment process of former Soviet military brownfields and urban sprawl in Hungary. Research findings highlighted the overall importance of the regeneration of military brownfields in urban development; however, not all the assessed projects appeared to be beneficial to densification objectives. We could identify two groups of brownfields lying within the boundaries of the compact city and outside the boundaries. The regeneration of military brownfields embedded in the built-up areas of cities can contribute to densification objectives and attract new functions and residents to abandoned areas. They can also support wider regeneration strategies of local governments, especially in run-down neighborhoods. However, a large number of military brownfields are located on the peripheries of metropolitan areas. The regeneration of such sites, as demonstrated by the case studies, can play a catalyst role in urban sprawl. Therefore, it is important to emphasize that local municipalities should make a careful strategic selection of military brownfield sites for redevelopment based upon their characteristics and location, as supported by the typology presented in this study, together with locally perceived socio-economic and risk factors.

The neon-sodium cycle of hydrogen burning occurs in several astrophysical sites, such as asymptotic giant branch stars and novae, affecting the production of neon and sodium isotopes. To enhance the accuracy of predicted nucleosynthesis yields, there is a pressing need for new experimental investigations of the cross sections of the reactions involved in this cycle at energies relevant to astrophysics. The 400 kV accelerator at the Laboratory for Underground Nuclear Astrophysics (LUNA) provides a unique advantage relative to above-ground laboratories thanks to its deep underground location within the Gran Sasso National Laboratory (INFN-LNGS) in Italy. We performed experiments at LUNA on two of the reactions of the NeNa cycle: $^{20}$Ne(p,$\gamma )^{21}$Na and $^{21}$Ne(p,$\gamma )^{22}$Na using a high-purity gas target system for isotopically enriched gases coupled with two high-resolution germanium detectors, surrounded by copper and lead shielding to further reduce the natural background at LUNA. We describe the detailed characterization of the experimental setup performed through Monte Carlo simulations, and the method for the precise determination of resonance energies, giving improved values of $E_{\textrm{r}}$ = 127.3 ± 0.5 keV, 271.4 ± 0.4 keV, 272.3 ± 0.4 keV, 291.5 ± 0.5 keV and 352.6 ± 0.4 keV. Additionally, decay branching ratios for the $E_{\textrm{x}}$ = 7016.4 keV excited state in $^{22}$Na, and three new transitions ($\textrm{R} \rightarrow 4770$ keV, $\textrm{R}\rightarrow 3059.4$ keV and $\textrm{R}\rightarrow 583.05$ keV) in the $E_{\textrm{r}}$ = 291.5 keV resonance, are also reported.

The dominant fraction of the extragalactic γ-ray sources are blazars, active galactic nuclei with jets inclined ata small angle to the line of sight. Apart from blazars, a few dozen narrow-line Seyfert 1 galaxies (NLS1) and a number of radio galaxies are associated with γ-ray sources. The identification of γ-ray sources requires multiwavelength follow-up observations since several candidates could reside within the relatively large γ-ray localisation area. The γ-ray source 4FGL 0959.6+4606 was originally associated with a radio galaxy. However, follow-up multiwavelength work suggested a nearby NLS1 as the more probable origin of the γ-ray emission. We performed high-resolution very long baseline interferometry (VLBI) observation at 5 GHz of both proposed counterparts of 4FGL 0959.6+4606. We clearly detected the NLS1 source SDSS J095909.51+460014.3 with relativistically boosted jet emission. On the other hand, we did not detect milliarcsecond-scale compact emission in the radio galaxy 2MASX J09591976+4603515. Our VLBI imaging results suggest that the NLS1 object is the origin of the γ-ray emission in 4FGL 0959.6+4606.

In a simplified laboratory model of a stratified ocean basin with colder and warmer water layers we investigate the propagation of gravity currents, internal solitary waves, and solibores excited along the pycnocline. The dynamics of these disturbances are observed with a thermal camera mounted above the free water surface – imitating infrared satellite-based remote sensing – and with a visible range camera from the side simultaneously, to provide “ground truth” information on the nonlinear waves via dye tracing for the validation of the method. Contrasting the large-scale temporal changes of the surface temperature field and the internal wave propagation we find that, despite the fact that the interface (pycnocline) is orders of magnitude deeper than the penetration depth of the observed infrared radiation, certain surface signatures of the interfacial wave dynamics can be detected in the water surface temperature fields due to secondary convective flows. Such a coupling may be applicable for the exploration of internal waves using infrared sea-surface temperature data from satellites.

The European Green Deal (EGD), a complex policy program meant to address climate change and ensure a “just, fair and inclusive” transition into a more sustainable and greener Europe, was launched by the EU in 2019. It was clear from the very beginning that the opportunities and costs of the ambitious green transition would be very uneven geographically, not only within the EU but also among its regions and locations. Regions with higher environmental stress and/or less technological and economic capacities will inevitably be disadvantaged. The EGD requires large-scale public acceptance, which comes with democratic innovations and participative practices, which are less embedded in many regions. The former socialist bloc still struggles today with establishing decent levels of public participation, as well as with adopting and implementing democratic community principles in practice. The main aim of this paper is twofold. On the one hand, we intend to give an assessment of where Central and Eastern European (CEE) countries stand in the process of the green transition and what the major focus areas affecting them are, based on the existing academic literature. On the other hand, we intend to give a clear overview of the causes for and aspects of the weakness of civil society in the post-communist bloc and reasons why the adaptation of democratic innovations is lagging in this region. For this purpose, a systematic literature search and bibliometric analysis was performed based on articles indexed in the Scopus and Web of Science databases. Altogether, 172 articles published in the region were filtered and systematically analyzed according to the main themes of the papers related to the EGD. Research findings show that the interests of researchers in CEE countries largely differ from those in the mainstream academic discourse. Research topics, high on the agenda in Western countries, are hardly present in the academic discourse in CEE countries. On the other hand, issues like energy efficiency, urbanization’s impacts on green growth and renewable energy development, and innovations towards a circular economy dominate the research agenda. This region started the green transition process with major handicaps compared to the West, connected to path dependency and the legacy of socialist structures. The paper analyses the bibliometric aspects of articles published on these topics and highlights the highly sectoral and country-focused approaches taken with regard to the EGD. In our paper, we highlight the importance of the region on a geographic scale, which goes beyond the initial framework and offers a different approach to addressing the issue. The paper proves that the presence of EGD-related participation processes is significantly lacking in academic literature in the CEE region. However, the most important finding of our paper is the identification of an academic gap regarding democratic innovations and deliberation, as well as regarding active involvement and participation of people in EGD-related programs. This gives an even more important base for the assessment of the region in terms of the EGD, which faces growing populism and advancing authoritarian regimes, such that public participation and citizen control have become vitally important for the implementation of the green transition.

Stromatolites can be traced back to ∼3.5 billion years. They were widespread in the shorelines of ancient oceans and seas. However, they are uncommon nowadays, and basic information is lacking about how these unique carbonate structures developed. Here we study the unusually thick (3–5 cm) biofilms of the 79.2 °C outflow from Köröm thermal well (Hungary) and demonstrate that its microbial mat – carbonate architecture is similar to fossilized microdigitate stromatolites. Our observations reveal vertically oriented fibrous mineral fabrics, typical of stromatolites, in the red biofilm and clotted mesostructures, typical of thrombolites, in the green biofilm. These layers contain carbonate peloids and show network structures, formed by filamentous microbes. The 16S rRNA gene-based amplicon sequencing implies that numerous undescribed taxa may contribute to the carbonate mineralisation. The biofilms abundantly contain the phyla Bacteroidota, Pseudomonadota and Cyanobacteria. Geitlerinema PCC-8501 and Raineya are characteristic for the green biofilm, whereas uncultured Oxyphotobacteria, unc. Saprospiraceae and unc. Cytophagales are abundant in the red biofilm. A hydrogen-oxidizing Hydrogenobacter within the phylum Aquificota and unclassified Bacteria together with the phylum Deinococcota dominate the water and carbonate samples. The morphological structure and taxonomic composition of Köröm biofilm is a unique representation of the development processes of microbialite formations.

Energy-saving and cost-efficient reaction routes to prepare highly active catalysts for CO2 hydrogenation or solid oxide fuel cells (SOFCs) are enormously important. In this paper, we report a detailed study of a dichromate salt of [Fe(urea)6]3+, a member of the [M(urea)6]3+ complex family (M = Fe, Al, Mn, Cr, V, or Ti) with oxidizing anions, which is a promising precursor of a Cr-rich mixed chromium iron oxide catalyst prepared at a low temperature in the solid phase. The single-crystal X-ray structure, various (infrared, ultraviolet–visible, and Raman) spectroscopic studies, and thermal analysis (differential scanning calorimetry and thermogravimetric analysis/mass spectrometry) of [hexakis(urea-O)iron(III)] dichromate {[Fe(urea-O)6]2(Cr2O7)3} and its decomposition products confirmed the presence of a quasi-intramolecular redox reaction between the urea ligands and dichromate anions. The redox reactions result in various mixed Cr–Fe oxides with amorphous structure, whereas above 550 °C, the crystal structure and composition of the final products depend on the atmosphere during the thermal decomposition. The iron–chromium mixed oxides are potential catalysts in CO2 hydrogenation that afford CO, CH4, C2H6, and C3H8. Furthermore, our Mössbauer spectroscopy studies show a possible electron hopping between the FeII and FeIII ions at the tetrahedral sites of the spinel structure, which suggests that the formed chromite is also a potential SOFC material. Our study also demonstrates that hexaureairon(III) dichromate is a selective oxidation agent of sulfur-containing organic compounds.

Asymptotic giant branch (AGB) stars play a significant role in our understanding of the origin of the elements. They contribute to the abundances of C, N, and approximately 50% of the abundances of the elements heavier than iron. An aspect often neglected in studies of AGB stars is the impact of a stellar companion on AGB stellar evolution and nucleosynthesis. In this study, we update the stellar abundances of AGB stars in the binary population synthesis code binary_c and calibrate our treatment of the third dredge-up using observations of Galactic carbon stars. We model stellar populations of low- to intermediate-mass stars at solar-metallicity and examine the stellar wind contributions to C, N, O, Sr, Ba, and Pb yields at binary fractions between 0 and 1. For a stellar population with a binary fraction of 0.7, we find $\sim$ 20–25% less C and s -process elements ejected than from a population composed of only single stars, and we find little change in the N and O yields. We also compare our models with observed abundances from Ba stars and find our models can reproduce most Ba star abundances, but our population estimates a higher frequency of Ba stars with a surface [Ce/Y] > $+0.2\,$ dex. Our models also predict the rare existence of Ba stars with masses $\gt 10\,\textrm{M}_{\odot}$ .

The radio source J0028+0035 is a recently discovered double–double radio galaxy at redshift z=0.398. Its relic outer lobes are separated by about 3′ in the sky, corresponding to ∼1 Mpc projected linear size. Inside this large-scale structure, the inner pair of collinear lobes span about 100 kpc. In the arcsec-resolution radio images of J0028+0035, there is a central radio feature that offers the intriguing possibility of being resolved into a pc-scale, third pair of innermost lobes. This would make this radio galaxy a rare triple–double source where traces of three distinct episodes of radio activity could be observed. To reveal the compact radio structure of the central component, we conducted observation with the European Very Long Baseline Interferometer Network and the enhanced Multi Element Remotely Linked Interferometer Network. Our 1.66 GHz image with high (∼5 milliarcsec) resolution shows a compact central radio core with no indication of a third, innermost double feature. The observation performed in multi-phase-centre mode also revealed that the physically unrelated but in projection closely separated background source 5BZU J0028+0035 has a single weak, somewhat resolved radio feature, at odds with its blazar classification.

The first missions to Mars may be followed by more extensive visits. Mission duration must comply with launch windows and time spent on the Martian surface would typically amount to 500 days. A safe and comfortable habitat will be required, along with a reliable supply of all necessary life-support materials (e.g., breathable air, potable water, food). Consumables transported from Earth will be recycled extensively. Water can also be mined on site, both for use as such and to generate oxygen. The latter could be used for breathing, but also for combustion fuel, both as a local energy source and for the return journey. Early crew habitats may gradually develop into long-lasting scientific outposts. Its most important tasks would be the scientific exploration of the geological and (putative) biochemical history of the terrain and to enable a more sustained presence by prospecting for in-situ resources. Such stays would pose unprecedented challenges to the crew’s physical and psychological endurance. It will also raise major legal and ethical questions, which require serious consideration before any such mission takes place.

If early crewed outposts on Mars can develop adequate habitats and in-situ resource utilization capabilities, they may evolve into small permanent settlements. Their main aims would likely remain scientific exploration, as well as work required for the settlement to grow further and become (nearly) self-sustained. Even if the latter work is successful, a settlement will raise multiple practical, legal, and ethical questions which did not apply, or not to the same extent, to missions smaller in scale. For example, living conditions (tight living compartments, high levels of ionizing radiation, partial gravity, etc.) could cause new medical problems over the long term, and be risky for reproductive biology, thus endangering the viability of the community. If humans were to spend decades on Mars, a return to Earth may be hazardous. Finally, the identity of the settlement, and its relationship with terrestrial operators, founders, and legal systems, may be complex and should be considered well ahead of time.

In this chapter, we discuss the comprehensive history and technological evolution of robotic missions to Mars, starting from the Cold War-era space race through to contemporary missions. We emphasize the major milestones achieved in Mars exploration, notably the first successful flybys and orbital insertions, and the deployment of increasingly sophisticated rovers and instruments. The discussion includes detailed accounts of both Soviet and American efforts, underscoring the many challenges they faced, such as rocket reliability and communication issues. The successes of these missions have substantially increased our understanding of Mars’s geology and potential for life, which is evident from the advanced scientific equipment deployed to the Martian surface in recent decades. Overall, despite early failures, the perseverance and international collaboration in Mars exploration have led to groundbreaking discoveries about the planet’s environment and history. Looking forward, the chapter outlines a possible future for Mars exploration: driven by technological innovations and international and private partnerships, humanity may uncover much about Mars in the years to come.

Public and private institutions are pursuing the very ambitious goal of landing humans on Mars, and returning them safely to Earth, in the near future. This goal is stimulated by international competition in spacefaring technologies, by the possibility of finding new natural resources, by the promise of groundbreaking scientific findings, and by a drive to expand the frontiers of human presence. However, major challenges remain to be overcome. First, interplanetary travel and a stay on Mars will challenge the psychology and physiology of humans; adequate countermeasures must be searched to ensure the health and wellbeing of astronauts. Then, a number of new technologies (heavy launch vehicles, nuclear propulsion vehicles, landing and ascending vehicles, radiation shielding, materials processing, life-support systems) require extensive development. These various requirements, together with high mission costs, render the first crewed missions to Mars challenging in their technical, economic, medical, and ethical aspects.

In the second half of the Late Neolithic (4700 − 4500 cal BCE), the first malachite and copper artefacts appeared in large quantities in the territory of present-day Hungary. They are known only as grave goods such as beads, rings and bracelets. Copper artefacts are concentrated in South-eastern Transdanubia, and archaeological literature has argued that this copper wealth may have been due to the exploitation of local malachite resources in the Mecsek Mountains. In our study, we compared lead isotope and chemical composition measurements of Mecsek malachite sources, Late Neolithic malachite and copper artefacts, and other potential ore sources to investigate the provenance of the raw material of these artefacts. The results of our analysis clearly exclude the exploitation of local, Mecsek sources. The malachite and copper artefacts found in the same grave may have come from the same source in the majority of the cases. This suggests that a set of ornaments was made using either technology. Among the potential sources, several mining regions emerged, primarily in the territory of present-day Bulgaria. A group of copper artefacts with high purity, common in contemporaneous Balkan sites, may come from a single source, which remains unknown. A smaller group of artefacts might be derived from the Bihor region. These results can be interpreted as a long-distance prestige exchange network, in which a composite set of ornaments were circulated in long distances and the source areas of the raw materials and the sites where they were finally deposited were not certainly directly linked.