Fig. 2: Observed and simulated ejecta cone edge geometries.
From: Elliptical ejecta of asteroid Dimorphos is due to its surface curvature
a–d Didymos-Dimorphos orientations seen from observers in J2000. The versions of the Didymos and Dimorphos shape models are Didyv00396 and Dimov00430. The green arrows give IAU_DIMORPHOS as a reference. e–h Images taken by observers (HST in e and LICIACube in f–h). The HST image captures the global structure of the ejecta cone, evolving toward the north (N) and southeast (SE), and the tail extended toward the northwest. All images are centered at Dimorphos. i–l Simulated cone geometry in light yellow seen from observers (HST in i and LICIACube in j–l). The ejecta cone, illustrated as a yellow cone with frames in black, exhibits its geometry differently in HST and LICIACube images. The cone observed by HST (i) does not change over the considered time, while that by LICIACube changes dynamically. LICIACube first sees the front side of the cone (j), where Dimorphos is hidden behind it. Once passing through it, the spacecraft observes its backside behind Dimorphos (k and l). The red arrows show the direction of the cone axis, while the blue ones represent the DART incidence angle. Column (a, e, i) shows HST measurement at T + 18,147 s = T + 5.0 h. Columns (b, f, j), (c, g, k), and (d, h, l) give LICIACube measurements at T + 160 s, T + 170 s, and T + 195 s, respectively.
