“…Apollinaris Mons is a volcanic edifice located between the northern lowland and southern highlands. It covers an area ∼190 km wide and features a large summit caldera and ∼140 km fan deposit extending to the southeast (Chuang et al., 2019 ; El‐Maarry et al., 2014 ; Greeley & Spudis, 1981 ; Robinson et al., 1993 ). A series of eight new ROTO observations were collected from 18:00 to 19:00 hr LTST, 38°–47° L s , 93°–102° solar incidence, and surface emission angles from −31° to +33° (Table 1 ).…”