by Matt Tarlach
Rumker is fascinating under low illumination, appearing as a low plateau surmounted by several low domes. Two domes near the north end appear steeper and sharper than the others, and along with a small, fresh crater seem to frame a small bay at the north edge of the plateau. (Lunar Orbiter imagery reveals one of the brighter northern "domes" is actually a cluster of small fresh craters). A soft-edged, approximately circular sunken area dominates the eastern portion of the plateau. Is this an eroded impact crater, or a volcanic collapse feature?
When right at the terminator, it appears that Wargentin is not quite completely filled with lava: shadows of the peaks along its eastern rim are joined by a line of black shadow that varies from bold to thread-thin, indicating a raised rim that is continuous on the eastern side though very low in places. Under low illumination the wrinkle ridges that cross Wargentin's interior appear soft, without crests, and show larger variations in height (as indicated by shadow lengths) than in width. A peak near the southern extremity of the crater was the first part of the western rim to catch the light, and seems to rise well above the flooded crater floor. The "peak" grew quickly in length and brightness as the sun rose, revealing itself as a ridge.
Posted on shallow-sky May 21, 2005 10:30:59 PT
Converted by report.pm 1.2 Sep 20, 2005 12:43:57 PT