Experiments Indicate Regolith Is Looser In The Lunar Polar Regions Than At The Lunar Landing Sites

Abstract

Since the Apollo program or earlier it has been widely believed that the lunar regolith was compacted through vibrations including nearby impact events, thermal stress release in the regolith, deep moon quakes, and shallow moon quakes. Experiments have shown that vibrations both compact and re-loosen regolith as a function of depth in the lunar soil column and amplitude of the vibrational acceleration. Experiments have also identified another process that is extremely effective at compacting regolith: The expansion and contraction of individual regolith grains due to thermal cycling in the upper part of the regolith where the diurnal thermal wave exists. Remote sensing data sets from the Moon suggest that the soil is less compacted in regions where there is less thermal cycling, including infrared emissions measured by the Diviner radiometer on the Lunar Reconnaissance Orbiter (LRO). Here, we performed additional experiments in thermal cycling simulated lunar regolith and confirm that it is an effective compaction mechanism and may explain the remote sensing data. This creates a consistent picture that the soil really is looser in the upper layers in polar regions, which may be a challenge for rovers that must drive in the looser soil.

Publication Date

1-1-2018

Publication Title

Earth and Space 2018: Engineering for Extreme Environments - Proceedings of the 16th Biennial International Conference on Engineering, Science, Construction, and Operations in Challenging Environments

Number of Pages

79-85

Document Type

Article; Proceedings Paper

Personal Identifier

scopus

DOI Link

https://doi.org/10.1061/9780784481899.009

Socpus ID

85091435757 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/85091435757

This document is currently not available here.

Share

COinS