Lunar Surface Change Detection

: Lunar Impact Flashes and the Resultant Craters

Abstract

Lunar impact flash (LIF) observations allow for the impactor flux in the Earth-Moon meteoroid environment to be studied, with greater opportunity to observe the less frequent impacts than ground-based meteor observations. The luminous efficiency, η, is the fraction of an impactor’s kinetic energy that becomes light, and is poorly constrained. Detection of the crater formed during a LIF gives ground-truth measurements for the refinement of the luminous efficiency. As only two LIFs with identified craters exist within literature, in this work software is developed for the automated detection of the formed craters from known LIFs, and the results from using this software with the 22 highest energy LIFs in literature are presented. Overall 12 craters were identified, nine of which could be linked to known LIFs. Using these craters and the known kinetic energy from six of the LIFs, the luminous efficiency was recalculated, which was found to be η=0.0171. Higher energy LIFs occur at a lower frequency, and therefore maximising the times in which LIF observation can occur is vital to catch these rarer events. Using current methods, LIF observations can only be performed during observer night time. In this work, the methodology to observe during local daytime by observing in short-wave infrared, and the first results from such observations, are presented. It was found that during the daytime, LIFs of Jmag=+5.6±0.18 (equivalent to Vmag=+6.7) should be detectable with the experimental set-up. This represents an increase in opportunity to observe LIFs by almost 500%.

Date of Award	2023
Original language	English
Awarding Institution	Aberystwyth University
Supervisor	Tony Cook (Supervisor) & Huw Morgan (Supervisor)