One night past the August full moon I had the opportunity to observe the craters near the moonâ€™s eastern limb. One of these craters, the one I selected for sketching, was the walled-plain crater Langrenus. With the terminator a couple of hundred kilometers away the beautiful ray system was still easily seen crossing Mare Fecunditatis to the west. Crater Langrenus is approximately 132 kilometers in diameter and dates from the Eratosthenian period. Its walls stand several kilometers tall and it has a nice pair of central mountain peaks rising more than a kilometer above the floor. The northern portion of the floor is heavily boulder covered but in the current lighting that was difficult to see clearly. Beyond the crater to the northwest the triplet craters of Naonobu, Bilharz and Atwood were nicely visible and a central swelling could be seen on the floor of each.
For this sketch I used: black Strathmore 400 Artagain paper, white and black Conteâ€™
pastel pencils and a hard blending stump.
Telescope: 10 inch f/ 5.7 Dobsonian with 6mm (241x) and 4 mm (362x) eyepieces
Date: 8-8-2009 6:50-8:15 UT
Temperature: 22Â°C (72Â°F)
Partly cloudy, calm
Seeing: Antoniadi III,
Co longitude 107.3Â°
Lunation 16 days
Libration in Longitude -3.5Â°
Oak Forest, Illinois