I have a image of the crater Albategnius, which is located just to the east of the well known Ptolemaeus/Alphonsus/Arzachel trio.
The central peak of Albategnius contains a small crater at the very top, however I can’t find any information (googling) on whether this is an impact crater or is related to volcanic in some way. If an impact it is a pretty damn nicely placed one!
Do any lunar observers have any information on this feature in their books?
Craig – I think Bill Leatherbarrow is the man for this. However, it is not the only summit “crater” on a central peak. I suspect that it is a collapse feature – a dimple – rather than an impact crater. That said, it does have a small impact crater within it! Have a look at this: https://commons.wikimedia.org/wiki/File:AlbategniusCraterPeak.jpg – Ray E. –
My guess would be that the central peak crater is just a perfectly positioned impact crater – the result of a ‘lucky strike’. Despite what Patrick Moore used to say, the ‘bomb’ does fall into the’bucket’ from time to time! I can see nothing to suggest the feature is of volcanic origin. The central peak complex is the result of ‘rebound’ following the impact that created Albategnius – it is not a volcanic cone with a summit caldera.
Sometimes, as in Gassendi’s central peak, what look like summit craters turn out to be just dimples between multiple peaks, but this one does indeed look like a proper crater.
Incidentally, the central peak complex appears to be off-centre, suggesting either that Albategnius might have been the result of an oblique impact or that the central peak was once a peak ring, the lower parts of which have been submerged beneath whatever has infilled Albategnius.