Bernadett D. Pál

This study reveals the effects of artificial space-like proton irradiation on three meteorite samples that are Northwest Africa (NWA) 4560 LL3.2 and NWA 5838 H6 chondrite meteorites, as well as the Dhofar (Dho) 007 eucrite. We used low-vacuum scanning electron microscopy (LV-SEM) and Raman Spectroscopy to examine the structure and composition of olivine and pyroxene grains in the meteorites before and after the irradiation events. This article focuses on the strongest and most intense irradiation, which was performed by protons up to 12 keV with a fluence value of 10¹⁹ ions/cm² that lasted ~30 h. According to the Raman spectra, significant lattice disruption in all analyzed silicates occurred, and a more extensive amorphous, glassy layer developed under the strongest irradiation conditions. Relative to the second irradiation, peak 1 (820.0 cm⁻¹) shifts slightly negatively (–0.46 cm⁻¹) with a small FWHM increase (+0.88 cm⁻¹), while peak 2 (850.3 cm⁻¹) shifts positively in both parameters (+0.40 and +4.04 cm⁻¹) in NWA 4560 olivines. In NWA 5838 olivines, both olivine peaks (820.5 and 850.8 cm⁻¹) shift positively (+7.40 and +7.90 cm⁻¹) and broaden (+2.75 and +4.29 cm⁻¹). In Dho 007 pyroxenes, peak 1 (997.1 cm⁻¹) shifts positively (+3.01 cm⁻¹) with an FWHM decrease (−0.46 cm⁻¹), peak 2 (669.7 cm⁻¹) shifts slightly negatively (−0.75 cm⁻¹) while broadening strongly (+29.23 cm⁻¹), and peak 3 (327.7 cm⁻¹) shifts positively (+0.86 cm⁻¹) with reduced FWHM (−4.55 cm⁻¹). Three characteristic amorphous bands appear in all examined meteorite silicates, located at ~550–1000 cm⁻¹, ~1100–1700 cm⁻¹, and ~1700–1850 cm⁻¹. Olivines in NWA 4560 and NWA 5838 exhibited similar responses across all irradiation events. In contrast, Dho 007 pyroxenes showed variable compositional changes without a consistent or well-defined pattern in our SEM dataset. The Fo decrease in our experiments likely results from preferential Mg sputtering in the olivine lattice, leading to relative Fe enrichment, similar to but more pronounced than after the first irradiation. Pyroxenes exhibit a comparable response, with Fs and En increasing and Wo sharply decreasing, reflecting preferential Ca loss relative to Mg alongside Fe enrichment. Investigating these processes improves the interpretation of planetary remote sensing data and advances our understanding of planetary surface evolution, while also clarifying how surface materials respond to space environmental conditions.

Water-ice occurs inside many minor bodies almost throughout the Solar System. To have an overview of the inventory of water-ice in asteroids, beside the general characteristics of their activity, examples are presented with details, including the Hilda zone and among the Trojans. There might be several extinct comets among the asteroids with only internal ice content, demonstrating the complex evolution of such bodies. To evaluate the formation of ice-hosting small objects, their migration and retention capacity by a surface covering dust layer are also overviewed to provide a complex picture of volatile occurrences. This review aims to support further work and search for sublimation-induced activity of asteroids by future missions and telescopic surveys. Based on the observed and hypothesized occurrence and characteristics of icy asteroids, future observation-related estimations were made regarding the low limiting magnitude future survey of LSST/Vera Rubin and also the infrared ice identification by the James Webb space telescope. According to these estimations, there is a high probability of mapping the distribution of ice in the asteroid belt over the next decade.

The joint evaluation of different meteor observation types supports a better understanding of both meteor phenomena and the terrestrial atmosphere. Two types of examples are presented in this work, linking ionospheric effects to specific meteors, with almost one-third of the meteors that emerged at high altitudes simultaneously recorded with an optical camera. Very few such observations have been realized as yet. With daytime fireballs, the recorded infrasound effect and the atmospheric blast produced shock-wave-related small earthquakes which were identified by a network of ground stations. An overview of these observational types highlights specific topics for which substantial improvements and discoveries are expected in the near future.