Date Thesis Awarded


Access Type

Honors Thesis -- Open Access

Degree Name

Bachelors of Science (BS)




Marc Sher

Committee Members

Kelsi N. Singer

David S. Armstrong

Rowan X. Lockwood


Extraterrestrial impact crater formation is important in many subfields of planetary science, including geochronology, planetary formation, and dynamic fragmentation theory. Current dynamic fragmentation theory lacks scale dependence and relies heavily on terrestrial data. Exploring a range of impact and ejecta velocities as is produced by cratering events on the Moon may bridge the gap between heavily terrestrial-based theory and planetary data. The secondary craters of secondary craters deemed “tertiary craters,” have been theorized, but planetary images have not been of sufficient resolution to effectively search for them until recently. Tertiary craters are formed by relatively low-velocity fragments ejected by nearby secondary crater events. We present a comprehensive analysis of 103 potential tertiary impact craters found around three secondaries associated with one lunar primary to the SSW of Glushko crater on the Moon. Of these 103 potential tertiary craters, 15 are exemplary tertiary craters, which are small, highly elliptical dents that can be traced back to a specific progenitor secondary crater, are at the appropriate radial angles to the secondary, and have a downrange boulder that likely created the tertiary. We compare the observed tertiary-producing boulder sizes to predictions from the scaling relations that estimate what size projectile at a given velocity is necessary to produce a given crater size and find them in agreement. We also provide Python code that indicates which primary craters might yield more theoretically visible tertiaries for study. The data presented here demonstrate that the scaling equations apply at much lower speed, size, and energy scales than previously thought.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.