Thursday, January 12, 2012

LROC: Craggy Peak, Impact Melts

Northern slope of one of four central peaks in Hayn crater, on the northern edge of Humboldtianum basin. Downslope direction is from top to bottom (North is down), image field of view is 594 meters, sunlight is from upper left. LROC NAC observation M128754462L, orbit 4108, resolution 0.54 meters from 51.78 kilometers. View the full size LROC Featured Image HERE [NASA/GSFC/Arizona State University].
Hiroyuki Sato
LROC News System

Due to the tremendous energy released by an impact event large portions of the target rock is melted. This impact melt forms distinctive flows and ponds both inside and outside of its parent crater. In many young craters the LROC NAC has captured deposits that look as if they formed yesterday.

Today's Featured Image is on the northern slope of the Hayn crater central peak. Due to the peak's steepness, it is rough and craggy. In many places on the peak wavy deposits are seen between crags and blocks; these deposits are most likely impact melt. Truly amazing, first the central peak formed then impact melt splashed down and coated it. If this interpretation is correct you can say that the peak formed in matter of a few seconds, quickly enough that melt that was thrown during the impact had not yet landed!  Quantitative measurements of these kind of spectacular outcrops, using new accurate topography from LROC NAC stereo will help reveal how impact craters form.

LROC QuickMap WAC monochrome 125 meter per pixel projection of Hayn and vicinty, centered at 64.34°N, 83.94°E. The yellow arrow indicates the locations of LROC Featured Image field of view [NASA/GSFC/Arizona State University].
Hayn is an exceptionally deep crater because it is situated just within the northern mountainous ring of 550 km-wide Humboldtianum basin, which extends far beyond its deep interior Mare Humboldtianum. The entire basin straddles the 90° east meridian, though Mare Humboldtianum is a nearside basin visible at favorable lunar librations. The floor of Hayn is 4.9 kilometers below global mean elevation and it's northern crater rim is still more than a half kilometer below global mean. The mountain directly north of Hayn, a worn remnant of the Humboldtianum basin rim is 2.3 kilometers above global mean, nearly a seven thousand meter change in elevation over the eighty kilometers between that massif and the center of Hayn. LROC Wide Angle Camera (WAC) 100 meter per pixel digital terrain model, color shaded relief, orthographic projection centered on 60° east [NASA/GSFC/Arizona State University].

Explore the craggy peak and impact melt deposits, both on the peak and the floor of Hayn crater, HERE.

Related Posts:
On the floor of Green M
Splash and flow
Ejecta in Tycho crater
Natural Bridge on the Moon!

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