Photoelectrons, which are produced by solar Extreme Ultraviolet (EUV) and X-ray ionization of various neutrals, are an important component of the dayside Martian upper atmosphere (e.g. Coates et al., 2011; Fox et al., 2008). The ionization process generates well-defined, unique features in the photoelectron energy distribution, characterized by several distinctive peaks at 22-27 eV related to the He II 30.4 nm line, which is the most intensive EUV emission line in the solar spectrum (e.g. Frahm et al., 2006b; 2006a). In addition, a reduction in photoelectron intensity occurs around 60-70 eV due to the rapid drop in solar radiation at wavelengths shorter than 17 nm (e.g. Peterson et al., 2016; Sakai et al., 2015). The above spectral features have been extensively observed over the past four decades (e.g.

The major energy source of the Jovian system is derived from its fast rotation, and its major particle source is from volcanic activities from Io (Bolton et al., 2015). In addition to being plasma sources, large moons embedded within the Jovian magnetosphere can act as candidates responsible for losses of magnetospheric energetic particles as well (Paonessa & Cheng, 1985). The net effect of how moons affect radiation intensities in their environment is determined by the balance of loss processes (such as the moon absorption time scale) and sources (such as how fast new particles are provided by radial transport or local acceleration). Therefore, the moon absorption of radially diffusing energetic particles is recognized as an important physical process that needs to be considered when evaluating the particle dynamics in the Jovian magnetosphere (e.g.,

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An analysis is conducted focusing on the bidirectional electron conics at 19-55 eV on Mars q BECs are more likely observed on the nightside and near strong crustal magnetic anomalies q 19-55 eV BECs are formed due to day-tonight transport along cross-terminator magnetic field lines q

The photoelectron peaks near 27 eV and 500 eV are investigated, related to HeII 30.4 nm ionization and O Auger ionization q The 500 eV peak intensity increases with increasing solar irradiance much more rapidly than the 27 eV peak intensity q The observation is consistent with a larger variability in solar radiance at shorter wavelengths