Volcanic ballistic projectiles on Earth, Mars, Venus, and beyond: An open-source, undergraduate-developed model to probe planetary atmospheres

Abstract:

Centimeter- to meter-sized ballistic projectiles are common during explosive volcanic eruptions on Earth and may occur or have occurred on other worlds with active or past volcanic processes. Such worlds include Mars, Venus, Io, Enceladus, and (possibly) Titan. On Earth, these projectiles pose threats to nearby populations and structures. Despite the hazards, the in-flight dynamics of projectiles and their impact features provide information about eruptions as well as the atmosphere through which they travel. For instance, a ballistic impact feature associated with an eruption deposit near the Home Plate feature on Mars suggests that the Martian atmosphere was much denser in the past than it is today (Manga et al., 2012). On our own world, ballistic trajectories and impact features have been used to estimate the dynamics of eruptions (e.g. Tsunematsu et al. 2019). While terrestrial volcanic ballistic projectile motion has been studied extensively using computer simulations, comparatively little numerical efforts have been performed in the context of planetary environments. Because the equations for projectile motion can be discretized with relative simplicity, the problem of a volcanic block flying through an exotic atmosphere provides an excellent introduction to numerical methods for undergraduate students in STEM fields. Here, we showcase an open-source, GUI-based program that allows students to investigate how ballistic projectiles travel in a wide range of planetary atmospheres subject to different drag formulations. Beyond teaching, we demonstrate the value of our work in research by providing refined estimates of the past Martian atmosphere based on the impact feature in the Home Plate deposit.