Semi-Automated Fragmentation Modeling of Jovian Impacts

Over the past 30 years, impact observations on Jupiter have provided unique opportunities to investigate the effects of mid- to large-sized collisions on atmospheres. In 1994, the Galileo spacecraft was in an advantageous position to observe the entry phase of Shoemaker-Levy 9's (SL9) fragments, while more recent impacts have been largely observed by amateur astronomers with Earth-based telescopes. Both Galileo and amateur astronomy return data in the form of light curves. However, these light curves make it difficult to discern certain dynamical properties associated with impacts. At the time of SL9, many of these properties were largely unconstrained. As a result, hydrodynamic models used necessary assumptions for initial conditions (Korycansky et al. 2006, Palotai et al. 2011). These assumptions lead to discrepancies between results. Following the impact of August 7, 2019, fragmentation modeling was used to match different properties to the observed light curve. This method gave the most probable velocity, entry angle, and density associated with the impact (Sankar et al. 2020). Fragmentation modeling can serve to provide those previously unknown parameters, which also include strength and terminal depth. By coupling fragmentation modeling with hydrodynamic modeling, it is possible to determine the entry and breakup of the impactor, as well as the atmospheric response to the impact. In this work, we implement the model fitting code Emcee, into the fragmentation model to iterate through different parameter combinations and generate the most likely scenario. We first test the expanded model with the  August 7, 2019 impact event, and further use it to study the November 15, 2023 impact. We find that the latter was likely of cometary origin with an entry angle of 24 degrees and an initial speed of 60 km/s. Furthermore, the final fit of the modeled light curve to the observed for this event agrees within 17% (see figure). The authors acknowledge support for this project by NASA's Solar System Workings Program (Grant No. 80NSSC22K1376).