Development of an Interactive Web-Based Simulation and Visualization Tool for Cometary Jet Modelling on Arbitrarily Shaped Nuclei

Understanding the morphology and dynamics of cometary gas jets is essential for interpreting optical observations, planning flyby, rendezvous and impact trajectories and inferring subsurface volatile emissions. However, conventional high fidelity gas and dust models require substantial computational resources, specialized software and offline rendering pipelines. We present a web browser native framework that enables real time interactive simulations and visualizations of cometary outgassing for arbitrary nucleus shapes, requiring minimal setup running on a local graphics processing unit (GPU) powered by WebGPU technology [1] .

The developed processing pipeline implements the nucleus surface thermal balancing solver adapted from the Space Imaging Simulator for Proximity Operations (SISPO) [2] ComaCreator module and research done by Marschall et al. [3]. This yields spatially resolved sublimation rates that identify active regions depending on the angle of incidence onto the nucleus. Due to the fact that the thermal balance and gas emission calculations are carried out on a per facet basis, the pipeline is agnostic to object geometry therefore any cosmic object represented as a triangular surface mesh at any resolution can be processed without modification. As we obtain surface emission rates, WebGPU integration allows for sophisticated determination of activity generation for cometary jets. Example parameters determined by the surface activity levels include emission rates, particle sizes and lifetime, directional spread and emission velocity. Since technology comes with a provided shading language, it is possible to leverage GPU capabilities in order to determine the movement of dust particles using compute shaders based on physical equations present in observed flyby scenarios.

Our current implementation of the web-based cometary activity model includes two modes - particle based and direction line based. This allows the user to tailor the simulation to specific scientific needs - streamlines allow for dust flow path visualization and jet trajectories, useful for quantitative analysis of jet origins and orientations while particle approach captures volumetric scattering and diffuse coma structures, offering realistic depiction of gas density variance and illumination effects. The interface is tailored with configuration parameters, which may be changed in real time to simulate various scenarios of comet activity. Adjusting any configuration re-runs the simulation nearly instantaneously, fostering rapid testing and analysis without recompilation or preprocessing. Preliminary results are showcased in figure 1 and 2, displaying potential approaches to jet formation and dust dissipation visualization.

Fig. 2. Example outputs from the direction line approach, showing two potential line convergence methods.

By developing a tool to perform cometary activity research on any modern browser, we empower mission planners, observers and educators to explore the cometary outgassing phenomena on various discovered or procedurally generated nuclei. It also serves as a tool to popularize and educate the public on the complex nature of cometary activity and dust emission in space.

References
[1] https://www.w3.org/TR/webgpu/
[2] M. Pajusalu et al. (2022) SISPO: Space Imaging Simulator for Proximity Operations. PLoS ONE 17(3): e0263882. https://doi.org/10.1371/journal.pone.0263882
[3] R.В  Marschall et al. (2016) Modelling observations of the inner gas and dust coma of comet 67P/Churyumov-Gerasimenko using ROSINA/COPS and OSIRIS data: First results A&A 589 A90. https://doi.org/10.1051/0004-6361/201628085