Last Sunday night I had the Celestron set up in the driveway for gathering more video imagery of the moon. The areas of interests this time were the craters Arazchel, Ptolamaeus and Alphonsus, Rupes Recta or the Straight Wall, and a curious chevron like feature I cannot recall noticing before. Instead of using the 3X TeleVue Barlow, I opted to use the 2X Barlow because the wider field of view was needed and the seeing was okay but not great. It also made finding the area I wanted to image easier. The moon was higher up in the sky, which also lessened the prism like color fringing that appears when it's close to the horizon.
The craters Ptolemaeus and Alphonsus nicely fit in the field of view. While both were flooded by mare lavas that erupted through faults onto the crater floors, Alphonsus still has a visible central peak while Ptolemaeus' central peak is buried under lava flows, if it exists at all. In 1965 the Ranger 9 probe crashed in the Alphonsus crater near it's central peak at 6,000 mph at the conclusion of it's successful mission. The probe was sent to take and images of the lunar surface back to mission control until impact. The goal of the Ranger lunar probes were finding out what the nature of the lunar surface was and to see if manned spacecraft could land there. Small craters are scattered across the floor of Ptolemaeus.
The trio of craters Cyrillus, Theophilus and Catharina are one of the most recognizable features on the moon even through binoculars.
The crater Arazchel was rapidly flooding with sunlight while sunrise is taking place at Rupes Recta or the Straight Wall at the right side of the image. The low sun angle at the site accentuates the rugged topography in the area around Rupes Recta, which led to the ground dropping 1,300 feet or 400 meters on one side of the fault relative to the other. The Straight Wall is not actually a wall at all, it's a 70 mile or 110-kilometer long thrust fault. Along it's length the slope is only about ten degrees or so, an astronaut can hike from the bottom to the top with ease. Hidden in the shadow is a shallow rille through which very fluid basaltic lava flowed. As the sun angle rises higher at the site, it becomes visible through small telescopes.