ExESS (Extraterrestrial Exospheres and Surfaces Simulations) is the project title under which numerical models and simulations are created to analyze exospheres and surface of extraterrestrial bodies in our solar system. While several models of the exospheres and surfaces individually exist, their interaction with one another is the focus of ExESS.
While not all of the bodies in our solar system can be modeled this way, those with a collisionless atmosphere, also called a surface-bounded exosphere, can be. Several targets like this exist, the most prominent one being Earth's Moon. Others include Mercury and asteroids like Ceres.
The model is written entirely in the high-performance computer language Julia and is continuously updated and extended to cover more targets as well as to include further physical and geochemical mechanisms.
Julia is a modern, high-performance programming language specifically designed for scientific computing, machine learning, and data analysis. It was developed by a team of MIT researchers and has been publicly available since 2012.
Julia is a dynamic language that enables fast and easy writing and execution of code. It has a wide range of built-in libraries for scientific calculations, machine learning, and data analysis, which allow for quick and efficient performance of complex analyses.
One of the unique features of Julia is its high performance. It is able to execute code almost in real-time, providing significant advantages over other languages such as Python or R.
Links: https://julialang.org
A surface-bounded exosphere is a thin atmosphere that is confined to the surface of a planet or moon, rather than extending out into space. It is characterized by very low densities of gas and extremely low pressures. Surface-bounded exospheres are created when the thin atmosphere is held in place by the surface of the planet or moon, rather than being able to escape into space due to the lack of a strong enough gravitational pull.