Wednesday, May 15, 2013

Small Pond in Fecunditatis

Unnamed crater floor at the western edge of Mare Fecunditatis. LROC Narrow Angle Camera (NAC) M167919653R, LRO orbit 9880, August 14, 2011. Image center 6.422°S, 43.747°E, field of view 561 meters across, angle of incidence 42.28° at 56 cm per pixel resolution, from 26.95 km [NASA/GSFC/Arizona State University].
Hiroyuki Sato
LROC News System

Today's Featured Image highlights an unnamed small crater (roughly 600 meters in diameter) observed at western edge of Mare Fecunditatis.

As seen in images further down, the higher reflectance (optically) immature ejecta blanket of this crater suggests a young age relative to the adjacent craters.

The crater walls are mostly covered by collapsed materials but the bottom still shows the original floor. The most remarkable feature is the central pit filled with impact melt (~100 m in diameter) with wrinkles on its surface. What are wrinkles telling us?

Full 56 cm per pixel resolution view of the crater of interest in Mare Fecunditatis, from LROC NAC M167919653R [NASA/GSFC/Arizona State University].
Most of the ejecta blanket from a mosaic of both the left and right frames (M167919653LR) of the LROC NAC observation, a field of view 2.06 km-wide [NASA/GSFC/Arizona State University].
Probably this is a quenched surface of melt flows that coalesced from multiple directions, and each wrinkle corresponds to the contact boundary of different flow units. The mushroom shape extending from south toward the center could have been the last flow unit that squeezed through the earlier arriving melt. Post surface cracking may also contribute resulting in these complicated patterns. Impact melts exhibit large variety in their final shapes due to their complicated rheology changing with time. It must be interesting to see how different or similar they are to the volcanic surfaces of active Hawaiian volcanoes.

LROC WAC monochrome mosaic (100 m/pix) of the western portion of Mare Fecunditatis, centered at 6.67°S, 43.73°E shows the NAC footprint (blue box) and location of the area shown at high resolution in the Featured Image above (yellow arrow) [NASA/GSFC/Arizona State University].
Explore the wrinkles on this tiny melt pond in full NAC frame for yourself, HERE.

Related Posts:
Channels And Fractures
Farside impact!
Crater in 3D!
Young Highlands Crater
Rippled Pond
Messy Crater

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