March 16, 2007

Jump to: navigation, search

A Screenfull of Craters

image by Bob Pilz

Some very good seeing and fortuitous lighting enabled me to get a high resolution view of the Orontius area. Orontius doesn’t seem to get imaged that frequently probably due to being close to more showy neighboring craters like Tycho, Walter and Stofler. What surprises me about this area is that despite it being a very old crater (VMA lists it as pre-Nectarian) and also being very close to Tycho and all its ejecta, there are still areas on the floor that have few craters (even on LO images). This is especially true of the NE part of Orontius F which appears to be of the same age. Sometimes I wonder if this is just chance or whether more recent lava flows have occurred though they would have to be very recent indeed to post-date Tycho. At the very top is Lexell which shows one prominent rille and looks as if it is a typical floor-fractured-crater although heavily covered with ejecta presumably from Tycho. Given that the crater wall on the north has been submerged in lava, I imagine this crater formed after Delandres with a tilt towards the north which allowed parts of the crater to be submerged when Deslandre later filled with lava.

Bob Pilz

Technical Details:
Dec 29, 2006, ~01:47UT. 200mm f/6 Newtonian reflector + Televue 3x Barlow + DMK 21BF04 B/W camera + ‘Blue’ IR-block filter, .20 arcsec/pixel, 30 fps, 1/44 sec, 600/6000; Processed in Registax, ImagesPlus, PS CS. Taken from Lat: 35 degrees 36 minutes N, Long: 82 degrees 33 minutes W, Elev:~850m.

Related Links:
Rükl chart 65
Bob’s website

Yesterday's LPOD: A Colorful Bay!

Tomorrow's LPOD: Eclipse Ring


Register, Log in, and join in the comments.