Have you found a reliable source for predicting seeing and transparency conditions?
Well, there are several weather web-sites and apps that have information on local seeing and transparency, -- but what is the most reliable for you depends on your location. Some I'm currently using (for Scandinavia) are: "Meteoblue.com" and the apps "Xasteria", "Sat24" and "Weatherology". The most reliable source for info on seeing and transparency however is just poking your head out the door, and if that looks good, have a quick look at the moon and/or a startest. This will tell you all you need to know.
The Southern Cratered Highlands have seen no major Imbrium mare-lava floodings, but are dominated by ancient impacts in the lunar terra crust. Some of the largest impacts in this area are the old Pre-Nectarian basin structures: Werner-Airy (VA: 500km ø) and Mutus-Vlacq (MV: 700km ø), but the large walled "Hell Plain" Deslandres (235km ø) can also be considered a smaller basin impact with a possible 70km ø inner ring.
The Nubium Basin bordering on the Highlands towards NW is also Pre-Nectarian (but older than Deslandres), and it was mare-filled in the great Upper Imbrian lava flows; The Highlands though, including the ancient basins VA and MV, were not flooded by the Imbrian basaltic lavas, but instead repeatedly molded and battered by impact cratering; This long-lasting bombardment has resulted in a zone of ancient fractured megaregolith (brecciation) down to on average 2km depth, overlaid by a ~10m layer of smoother regolith plains material from the cratering ejecta consisting of impact melt and pulverized crust.
As an example, the floor of Deslandres is rough, pockmarked by several medium-size primary craters: Lexell, Walter W, Hell ("ghost", A, B, C) and on top of that, pitted by countless smaller secondary craters, some in chains (catenae) and clusters, like the one that includes Cassini's "bright spot". Also note the 110km long (unnamed) trough (valley) running diagonally from NW towards NE, -- radially to Imbrium, which may indicate the origin of this formation.
A couple of patches towards the NE on the Deslandres crater floor are smoother and darker than the rest, maybe caused by non-mare volcanism. Some surrounding craters - including Regiomontanus, Walter and Stöfler - have larger areas with smooth (young) floors, possibly formed by dark non-mare volcanism and later streaked with light hued impact ejecta (?).
Edited by AllanDystrup, 11 April 2021 - 05:56 AM.