Lunar Reconnaissance Orbiter Camera

Near the Summit of Malapert Mountain

The lunar highlands exhibit rhythmic patterns thought to result from slow, downslope creep of the loose regolith (soil). These subtle patterns are most easily seen when the Sun is low to the horizon. Image is 2400 meters wide, north is to the top [NASA/GSFC/Arizona State University].

What exactly is the cause of these intersecting lines, sometimes informally known as "elephant skin"? LROC is now collecting the data to allow scientists to model different theories. These include seismic shaking and temperature cycling. Most likely both mechanisms play a role, but which mechanism is more important?

Malapert mountain is very ancient, and thus has well-developed regolith (soil). Malapert is always seen at low Sun due to its latitude (86° South) near the south pole, giving this texture its striking appearance.

Currently LROC is building up mosaics of both poles and acquiring stereo data to provide high-resolution topography. Images of the same area with lighting from different directions combined with the new high-resolution topography maps are providing the tools to model the processes involved in forming these patterns. Stay tuned as the elephant skin story develops!

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