Erosional and Depositional Processes at the Lunar Surface

Abstract

Chandrayaan-1 X-ray Spectrometer high energy data were used to measure the width of the Earth’s magnetotail comparing this measured value with measurements from a computational magnetohydrodynamic model, known as the Open Geospace General Circulation Model. The data from C1XS were taken from the high energy channels of the device, where a large spike in count rates represents an influx of energetic particles with energies above a few MeV, which become minimum ionising particles and deposit energy in the detectors at the 18-19 keV range. The C1XS data and OpenGGCM data agree on a magnetotail width of between 50RE and 70RE fluctuating with the strength of the solar wind. An analysis of the distribution of transient lunar phenomena was performed with the intention of studying two theories relating to the origins of TLP. The first theory is that TLP are caused by outgassing at the boundary between lunar highland and mare terrains. Previous studies have been conducted suggesting a correlation between TLP locations and these mare borders, but it was found in this analysis that this correlation does not appear in the most robust and reliable data and that this correlation can be created or removed depending upon the decision to classify the Aristarchus Plateau as a highland terrain. The second theory studied is the creation of TLP from the splitting of rocks on the lunar surface. It has previously been calculated that rocks splitting from thermal stresses or meteoric impacts could create a piezoelectric effect exciting gases released from the cracks and creating a flash visible from Earth. This analysis used a NASA database of lunar impact flashes to search for any clustering of reports that would be a signature of a localised environment susceptible to rock fracturing. The analysis found no evidence of any localised effects and an impact catalogue consistent with a randomly distributed dataset, suggesting the proposed TLP explanation is either a rare occurrence or produces light obscured to an Earth observer.

Date of Award	2021
Original language	English
Awarding Institution	Aberystwyth University
Supervisor	Tony Cook (Supervisor) & Manuel Grande (Supervisor)