Top: From left to right, the pre-, during-, and post-flare solar EUV and SXR spectra adapted from Thiemann et al. (2018) over the wavelength range 0.5–189.5 nm. The pre-flare spectrum (gray) is superimposed on the during-flare spectrum (red) for comparison. Middle: From left to right, the pre-, during-, and post-flare Martian upper atmospheric structure in terms of the CO₂ (black), O (red), CO (orange), and N₂ (green) density profiles, all constructed with the aid of the MAVEN NGIMS measurements. Bottom: From left to right, the pre-, during-, and post-flare photoelectron energy spectra modeled with a two-stream kinetic approach at 150 km (blue) and 200 km (red), respectively, in both the upward (solid) and downward (dashed) directions. Note that the photoelectron spectra in the two directions are nearly indistinguishable at 150 km.