October 28, 2009
Tall Tales
image by Wes Higgins
| This is a tall image of treasures. Jansen, with its pond of smooth lava, sits on a well defined - with low lighting such as this - slight mound with lobate edges. It looks like the mound is centered on the crater, and since the mound is obviously mare lavas, it is tempting to ask if Jansen is a caldera. But its probably just an impact crater filled with lava. The ghost crater, Jansen R, presumably is another impact feature completely submerged by lava, although if anything is of volcanic origin this could be. The Jansen Rille appears to start on the rim of the large ruined crater at upper right and flow westward until it is truncated by the flowy rim of Jansen R. A straight and narrow rille west of Jansen E is matched by another south of Carrel. These are unusual rilles, probably not channels made by the flow of lava, but perhaps extension cracks above volcanic dikes (dykes for our British readers). The bottom third of the image is dominated by four quasi-parallel mare ridges trending to the northwest. Notice how they disappear at a broad oval cut by the craters Ross E, F and G. Fainter ridges continue above the oval - this suggests that it could be a buried crater that disrupted the ridges. Finally, the crater Arago E is decidedly elliptical - the high Sun Clementine view suggests it resulted from a low oblique impact rather than simultaneous double impacts.
Yesterday's LPOD: Hard Landers Tomorrow's LPOD: Not Vesuvius COMMENTS?Register, Log in, and join in the comments.
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