Understanding the origin of the double wings seen for some moths, as seen in the upper left panel of Figure 6 (see also the middle right panel of Figure 9 for another version of the double wing morphology). Double wings appear when all dust grains share practically the same periastron and apsidal line (x-axis) as a consequence of being launched only at parent body periastra. Top: scattered light image of the same disk featuring double wings, but seen face on here. Emission near periastron generates the upper set of wings in Figure 6, while the pair of jet-like features displaced symmetrically above and below the apsidal line produces the lower set of wings. Bottom: same as top, but plotting individual dust grains. Local overdensities generated at two orbital azimuths correspond to the two jets seen in the top panel.