2011 08 10, Delisle and Diophantus
2011 08 10, 0110-0208 UT Delisle and Diophantus
Geological period: Eratosthenian (-3.2 billon years to –1.1 billion years), Rukl 19
PCW Memorial Obsv., OH – Erika Rix
Zhumell 16” f/4.5 on a Dobsonian mount, 7mm Zhumell, no filter, 257x
Temp: 22.8 C, 79% H, Clear turning to 70% overcast with lightening and thunder, T: 5/6, S: Antoniadi II
Phase: 44.4 deg, Lunation: 10.27 days, Illumination: 85.7%, Colongitude: 40.2deg
Lib Lat: -00deg24m, Lib Long: +05deg35m
Alt: +24d21m, Az: +161deg13m
Eyepiece sketch on white cardstock with charcoal. Unfinished sketch due to lightening, thunder, and overcast skies rolling in.
Located in Mare Imbrium, Delisle (27 km) and Diophantus (19 km) are both relatively young impact craters. Delisle has a tormented floor with central mountains, sharp rim and high walls with a height of ~2550 m. Diophantus looks to be a simple crater with sharp rims, steep wall with a height of ~2970 m, and craterlet Diophantus C to the SW.
There is slight elongation of the features during my observation due to this area’s position near the northern lunar limb. You can see the obvious difference when compared to Apollo’s Image below. My eyepiece view will need to be rotated 180 degrees to match the orientation of NASA’s image.
Photo Credit: NASA
Rima Diophantus and crater Louise were not apparent, although Louise’s ray reached E-W extending beyond Diophantus B and a hint of it reaching to Artsimovich. A scalene triangle-shaped patch seemed to form a plateau between Diophantus, eastern edge of Mons Delisle, the SW edge of Delisle, and the western edge of Louise. Fedorov was only noticeable by the shadowing just north and south of it. Artsimovich was very obvious with its deep shadow. Diophantus, although only 6 km, was very clear as well with brightened areas extending north and south of it.
Additional reading:
Lunar and Planetary Institute, Apollo Image Atlas – AS15-M-2075
APOLLO OVER THE MOON: A VIEW FROM ORBIT (NASA SP-362)
PCW Memorial Observatory - Erika Rix 