DESIGNING A LOW-COST, LOW-VELOCITY IMPACT CRATERING LABORATORY FOR USE IN UNDERGRADUATE CLASSES AND RESEARCH

Volcanism, tectonics, weathering, and impact cratering are the four general geologic processes which shape the surfaces of every solid body in our solar system. On Earth, the effects of impact cratering are minimized because our atmosphere burns up many incoming projectiles and our tectonics and weathering processes erode, bury, or otherwise destroy impact craters. Perhaps for these reasons, impact cratering is generally not covered in as much depth in a typical undergraduate geology curriculum. However, students are fascinated by impact cratering and the process can be used as a means to engage students in planetary or terrestrial geology and also introduce them to the difficulties inherent in studying a complex geologic process in the laboratory.

Due to the high costs and safety issues of creating a true impact cratering lab, it is difficult to directly demonstrate the effects of impact on terrestrial planets to students in a laboratory setting. A variety of low cost impact experiments can be conducted in educational laboratories to explore the effects of drop height (i.e., impact speed), projectile density, and impact angle on final crater dimensions. Although effective for teaching about the relationship between crater size and the velocity and density of the projectile, the scope of these experiments is limited. Our goal is to maximize the amount of science that can be done in simple experiments by using projectiles that would fail on impact (e.g., paintballs) and low-cost high-speed camera systems to observe and quantify various aspects of the impact, such as the movement of the growing ejecta curtain.

This contribution describes the initial attempts at building an impact cratering lab at Winona State University, Winona, MN, using common and low-cost materials. The WSU impact cratering lab is designed using less than $400 for startup costs and supplies and will require minimal funding for continued experimenting. While the impact speeds attained are still well below normal impact speeds on planetary surfaces, this laboratory provides undergraduate students a place to begin exploring the impact cratering process at low velocities and designing experiments to study complex geological problems in the laboratory.