Date of Award

Spring 11-17-2018

Document Type


Degree Name

Doctor of Philosophy (PhD)

First Advisor

Nicholas Schneider

Second Advisor

Dave Brain

Third Advisor

Ian Stewart

Fourth Advisor

Fran Bagenal

Fifth Advisor

Mihaly Horanyi


This thesis investigates the interaction of cometary atmospheres (coma) and debris streams (meteor showers) on Mars' atmosphere. In this work, we use the close encounter of Comet Siding Spring (C/2013 A1) with Mars to investigate delivered cometary gas and dust. This serendipitous encounter occurred at a distance of 141,000 km, three times closer than distance between Earth and the Moon and was observed by the Imaging Ultraviolet Spectrograph (IUVS) on the Mars Atmosphere and Volatile EvolutioN (MAVEN) Mission. The gaseous coma enveloped the planet and Mars passed through the comet’s fresh debris stream, bombarding the upper atmosphere with cometary dust particles. Dust particles are liberated from comets as gas sublimates from their surfaces, and these particles evolve according to their size to form the interplanetary dust environment. As these interplanetary dust particles sporadically enter the Martian atmosphere, they ablate and form a layer of meteoric ions, and we detail this discovery and its implications.

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