Thermal weathering and fragmentation insights on aristarchus crater

Understanding the geomorphological characteristics and post-impact alterations of lunar craters remains critical for unraveling the Moon’s geological history. As advanced remote sensing imagery now offers a powerful approach to systematically address this gap, in this study, the Aristarchus Crater on the Moon is examined using Lunar Reconnaissance Orbiter Camera (LROC) images to map and identify geomorphological features. The research focus on the mechanical disintegration of boulders emphasizing thermally driven exfoliation as a dominant weathering process. The Moon’s wide diurnal temperature fluctuations, from ~100 K to 400 K generate significant internal stresses due to differential thermal expansion and contraction in surface rocks. By including major rock properties, thermal conductivity, thermal expansion coefficient, and elastic modulus stress intensity factors (KI) were simulated under different slope conditions. Our results show that KI values frequently exceed the fracture toughness (KIC) of common lunar lithologies, particularly on the steep crater wall, affirming that exfoliation is a principal mechanism of post-emplacement boulder degradation. These findings demonstrate that thermal fatigue play a crucial role in the ongoing alteration of the lunar surface and the crater’s interior and confirm exfoliation as a major geomorphic agent sculpting the interior of the crater, and elsewhere on the lunar surface.