Did A River Run Through It?
Explanation:
The lunar maria are composed of untold numbers of lava flows, but only rarely are the actual flows, or more accurately, their margins, detectable. Looking at Mike Wirths’ latest image of the region at the west end of the Cauchy Fault suggests that perhaps we can glimpse the remnants of a broad lava flow field. Between the craters Sinus and Sinus H the mare surface is textured and lineated with a “flow” pattern from the left to the right. The two outer lines shown on the mouseover image could be the margins of a lava flow field. Possible sources for flows could be the many domes (such as the one left of Sinas H & J) in this area. No lunar dome has yet been observed to be the source of a lava flow, but small shield volcanoes on Earth often are. Other things of interest in this wonderful shot (besides the many domes and swells) are two possible collapses (one just above Sinas in this view) and another left of the dome Cauchy Tau. Also, the area between Tau and the unnamed dome to its left is brighter and rougher than the surrounding maria – why? This image demonstrates that even though there have been many excellent previous views of an area, that a new image with different lighting can reveal features that were previously unknown. Perhaps someday we will get a low sun, high resolution SMART-1 view, but in the meantime I await the next spectacular amateur image!