A framework to predict Low- to High-Energy Neutral Atoms (LHENAs) Observations in Support of Planetary Exploration

Imaging of fluxes of Energetic Neutral Atoms (ENAs) had provided a means to improve our understanding of global magnetospheric and heliospheric processes since the mid-1990s.  The remarkable science results from ENA-imaging-based studies of magnetospheres from missions such as IMAGE (2000-2005) and TWINS (2008-2016) at Earth and Cassini (2004-2017) at Saturn had made ENA imaging a well-established and popular technique in space physics research. ENA imaging continues today with missions like IBEX (Interstellar Boundary Explorer) and Mars Express, interplanetary spacecraft en route to Jupiter (JUICE) and Mercury (BepiColombo), and upcoming IMAP (Interstellar Mapping and Acceleration Probe). We review our efforts to adapt a simulator of ENA production to predict Low- to High-Energy Neutral Atoms (LHENAs) observations from imagers in support of planetary exploration. We emphasize the key steps implemented into our simulation tool to enhance our computational capability to predict and/or analyze the detection of neutral atoms with energies of 100's of eV to 100's of keV that are produced in the magnetospheres of Jupiter, Saturn, Uranus and Neptune. We discuss the different models of ions, neutral species and magnetic fields used in our LHENAs simulator. We present results from different case studies to highlight the capability of our simulator to assist in the planning and interpretation of data from future, ongoing, and past planetary missions. We compare results of our simulator with Cassini ENA observations for validation purposes and show our LHENAs predictions for the JUICE mission, as well as for future exploration of the ice giants. We also discuss our path forward for future investigations of Earth's and Mercury's magnetospheres.