Lunar Outgassing, Transient Phenomena and The Return to The Moon, III: Observational and Experimental Techniques

TL;DR

This paper reviews observational and experimental techniques to study lunar outgassing and transient phenomena, proposing new methods to better understand lunar volatiles, their detection, and their implications for lunar science and exploration.

Contribution

It introduces a range of innovative observational and in-situ techniques for probing lunar outgassing, some of which are being implemented for the first time.

Findings

Remote sensing can detect outgassing related to TLPs.

Some outgassing remains trapped in lunar regolith, not surface-visible.

Proposed techniques can enhance understanding of lunar volatiles and their role in lunar evolution.

Abstract

In Papers II and III we show that Transient Lunar Phenomena (TLPs) are likely related to lunar outgassing, albeit in ways not fully understood. Here we propose a path forward, in which current and forthcoming technologies provide a more controlled, sensitive probe of lunar outgassing. Many of these techniques are being realized for the first time. Given the optical transient/outgassing connection, progress can be made by remote sensing, and we suggest programs of imaging, spectroscopy and combinations thereof. However, as found in Paper II, many aspects of lunar outgassing seem covert in nature. TLPs betray outgassing, but not all outgassing produces TLPs. Some outgassing may never appear at the surface, but remain trapped in the regolith. We also suggest more intrusive techniques, from radar mapping to in-situ probes. Understanding these volatiles seems promising in terms of a resource for humans on the Moon and beyond, and offers an interesting scientific goal in its own right. Hence this paper is a series of proposed techniques, some in practice, some which might be soon, and some requiring significant future investment, some of which may prove unwise pending results from predecessor investigations. These point towards enhancement of our knowledge of lunar outgassing, its relation to other lunar processes, and an increase in our understanding of how volatiles are involved in the evolution of the Moon. We emphasize certain ground-based observations in time for flights of SELENE, LRO and other robotic missions, and others before extensive human xploration. We discuss how study of the pristine lunar atmosphere pertains to understanding the role of anthropogenic volatiles, an important confusing signal