Abstract: Lunar regolith combines a wide compositional range, a broad and repeatedly reworked particle-size distribution, and depth-dependent shear strength, yet these three properties are almost always reported separately in the literature. This study applies Shannon entropy to two of these properties for five Apollo landing sites (12, 14, 15, 16 and 17): the bulk oxide composition of returned fines, and the dispersion of published particle-size statistics. A normalized compositional entropy and a granulometric variability index are computed for each site and combined into a composite SelenEntropic Resilience Index (SERI). Mare-influenced sites with a comparatively even mix of oxides score highest on compositional entropy, while the anorthosite-rich Apollo 17 soil, dominated by a single oxide group, scores lowest. Apollo 14 stands apart on the granulometric side, showing far greater dispersion in reported grain size than any other site, a pattern traceable to known sampling heterogeneity near Cone Crater ejecta. The resulting SERI values are discussed alongside independently reported lunar geotechnical parameters, bulk density, internal friction angle and cohesion, to indicate where compositional or granulometric disorder may warrant closer geotechnical attention before excavation, foundation work or in-situ resource utilization at a given site. The index is presented as a first-order screening tool built entirely from published NASA and peer-reviewed data, and the additional site-resolved sieve and shear-strength measurements needed to extend it into an operational design parameter are identified.

Keywords: Apollo regolith; compositional entropy; geotechnical stability; granulometry; in-situ resource utilization; lunar soil mechanics; particle-size distribution; Shannon entropy.

Title: SelenEntropic Resilience: An Entropy-Based Assessment of Lunar Soil Stability Using NASA Data

Author: Dr Nikolaos Toumasis

International Journal of Novel Research in Engineering and Science

ISSN 2394-7349

Vol. 13, Issue 2, September 2026 - February 2027

Page No: 1-7

Novelty Journals

Website: www.noveltyjournals.com

Published Date: 02-September-2026