LROC: Jackson Waves

Waves of impact melt in Jackson crater, prominent in the farside lunar highlands. The Sun has risen high over the southeastern rim, beyond the lower right hand corner. LROC Narrow Angle Camera (NAC) observation M112658386R, LRO orbit 1736, November 16, 2009; illumination incidence at 46° resolution 54 centimeters per pixel. View the full-size LROC Featured Image HERE [NASA/GSFC/Arizona State University].

Sarah Braden
LROC News System

Within a terrace in Jackson crater impact melt formed a surface reminiscent of waves against the shore of a beach. The waves in today's Featured Image are cooled impact melt flow fronts, frozen in time on the lunar surface. The boulders are parts of the impact melt that have weathered out of the solidified rock over time. Jackson crater is a 71 km diameter impact crater located on the far side of the Moon (22.4°N, 163.1°W). A few milliseconds after the initial impact that formed Jackson crater, the crater walls slumped toward the center of the newly formed crater, creating a number of terraces. Next, impact melt (excavated, heated, and thrown above the crater) landed haphazardly over the lunar surface around and inside Jackson crater. If the melt lands on a slope it flows downhill as it cools. When melt lands on a relatively flat surface, like a terrace, it may slosh and flow for a while, but eventually it will create an impact melt pond. Impact melt ponds are found on crater floors, terraces, and in the surrounding area around a crater.

Jackson (22.4°N, 196.9°E) is 71 kilometers in diameter. The red box frames the full LROC NAC observation detailed above as the LROC Featured Image, August 8, 2011. View the full-size LROC WAC context image HERE [NASA/GSFC/Arizona State University].

Three LROC NAC observations swept up during various opportunities during the two-years LRO has spent in lunar orbit, are shown draped over a Wide Angle Camera 604 nm band mosaic stitched from overflights in LRO orbits 7819 through 7824, on March 5, 2011; Jackson crater as seen under a full Sun. See a larger version HERE [NASA/GSFC/Arizona State University].

Look in the full NAC frame for more exciting impact melt flow fronts!

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Jackson viewed through NHK's high-definition television from the 100 km high vantage of Japan's lunar orbiter Kaguya in late 2007. See the full-size image release HERE [JAXA/NHK/SELENE].