Evaluation of simulated space weathering based meteorite alteration and potential influence on mechanical deformation of rubble pile asteroids

Akos Kereszturi ^1* Ildikó Gyollai ¹ Sandor Biri ² Zoltán Juhász ² Csilla Király ³ Richard Rácz ² Dániel Rezes ¹ Béla Sülik ² Máté Szabó ¹ Zoltán Szalai ¹ Péter Szávai ¹

• ¹ Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences (MTA), Budapest, Hungary
• ² Institute for Nuclear Research (MTA), Debrecen, Hungary
• ³ Geographical Research Institute (MTA), Budapest, Hungary

Asteroids with the potential to impact Earth have become a significant focus of scientific research and applied space technology. These bodies are expected to be key targets for mitigation actions and space mining activities in the coming decades. Understanding their material characteristics is challenging due to the effects of space weathering, which alters the mineral composition and structure of their surfaces, resulting in feature poor infrared spectra. This study details laboratory tests of artificial solar wind effects on meteorites, revealing key changes, including decreasing magnesium content in olivine, water-loss-induced mineral changes, and general amorphization of the crystalline lattice. While these alterations affect only a thin surface layer (and not the bulk regolith volume) of the grains exposed of asteroid surfaces, they can influence the mechanical properties of most small (100 meter-class) asteroids by their physical surface contacts, as most small asteroids are rubble piles, witnessing rotation and related shape-altering grain migration and surface mixing. The mechanical properties of only a very thin surface layer of specific grains are influenced, however the behavior of granular aggregates with such influenced surfaces could be mixed by the YORP effect. This study reviews established findings, explores potential implications for asteroid behavior, and identifies future research directions.