Electronic Thesis and Dissertation Repository

Degree

Doctor of Philosophy

Program

Planetary Science

Supervisor

Dr. Gordon Osinski

Abstract

The impact cratering record on the Moon is important for many reasons, from understanding early solar system chronology to probing the lunar interior. In order to maximize scientific return from future lunar missions, it is useful to: 1) study terrestrial impact craters to better understand impact processes and products, and 2) develop appropriate human and robotic exploration strategies aligned with geological goals.

This research shows that the intermediate-size Mistastin Lake impact structure, in northern Labrador, Canada, is an unparalleled lunar analogue site, which includes both an anorthositic target and an almost complete suite of impact lithologies, including proximal ejecta deposits. New remote sensing, field mapping, and microscopy data are used to develop new structural and geological models of the Mistastin Lake impact structure. The results of this study show that a multi-stage ejecta emplacement model is required to explain the observations. It is also shown that impact melt-bearing breccias or “suevites” at Mistastin were emplaced as flows, were never airborne, and were formed from the mixing of impact melt flows with underlying lithic materials.

In order to maximize scientific return from future lunar missions, this work also focused on developing appropriate human and robotic exploration strategies aligned with geological goals. We show that precursor reconnaissance missions provide surface geology visualization at resolutions and from viewpoints not achievable from orbit. Within such a mission concept, geological tasks are best divided between fixed-executional approaches, in which tasks are fairly repetitive and are carried out by an unskilled surface agent, and an adaptive-exploratory approach, where a skilled agent makes observations and interpretations and the field plan can adapt to these findings as the agent progresses. Operational considerations that help increase scientific return include: extensive pre-mission planning using remote sensing data; defining flexible plans and science priorities to respond to changing conditions; including mutually cross-trained scientists and engineers on the field team; and adapting traverses to accommodate field crew input and autonomy. A phased approach for human exploration proved successful in incorporating astronaut feedback and allowed more autonomy for astronauts to determine optimal sampling localities and sites for detailed observations.


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Geology Commons

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