Today's Featured Image highlights an unnamed fresh crater (about 700 m in diameter) found on the western edge of Mare Smythii. The low reflectance materials extend out in an distinctive bell shaped pattern from the southwestern edge of the crater rim. The interior crater wall near this deposit also shows splashes of relatively darker materials, as well as three other dark patches at 12, 2, and 5 o'clock, relative to the crater center. These deposits are likely similar in nature to the excavated dark deposits emplaced near the rim, and they appear to have partially flowed back into the cavity.
Normally, ejecta travels radially from the impact center, resulting in lineations in the ejecta or rays pointing away from the source crater. In this bell shaped deposit, however, the two main dark lines outlining the bell are curved and extend about 150-200 m outside of the rim. Note that the surrounding terrain of this unnamed crater is nearly flat (see next WAC context); there are no readily apparent obstacles that might have affected the ejecta trajectory. Perhaps the original low reflectance deposits were unevenly buried, resulting in the curved dark patterns after excavation and final emplacement. What is the darker material? Since the crater is near the highland / mare boundary we might be seeing dark basalts or pyroclastics mixed with bright anorthositic crust.
Explore this enigmatic dark ejecta deposits in full NAC frame and find your own scenario!
Dark Craters on a Bright Ejecta Blanket
Rima Bode: Constellation region of interest
Dark-haloed crater in Mare Humorum
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