Electronic Thesis and Dissertation Repository


Master of Science



Collaborative Specialization

Planetary Science and Exploration


Neish, Catherine D.


Impact cratering is an abrupt, spectacular process that occurs on any world with a solid surface. On Earth, these craters are easily eroded or destroyed through endogenic processes. The Moon and Mercury, however, lack a significant atmosphere, meaning craters on these worlds remain intact longer, geologically. In this thesis, remote-sensing techniques were used to investigate impact melt emplacement about Mercury’s fresh, complex craters. For complex lunar craters, impact melt is preferentially ejected from the lowest rim elevation, implying topographic control. On Venus, impact melt is preferentially ejected downrange from the impact site, implying impactor-direction control. Mercury, despite its heavily-cratered surface, trends more similar to Venus than the Moon, but, unlike Venus, shows no downrange preference. This suggests impactor velocity is the controlling factor. Future work should study other rocky bodies in the Solar System, including Mars and Vesta, in order to better understand impact melt emplacement on terrestrial planets.