I'm looking at Pontamus E right now (Sunday May 12, 9:14pm). Very easy to make out its concentric structure at 364X in my 7" Intes Mak. I struggled make out the concentric structure at under 110X.
What is very interesting is Pontamus E is much shallower than the craters around it, including those smaller in diameter - evidence of the volcanic material that had pushed up from underneath, lifting the floor of the crater. Fascinating stuff!
The shallow nature of these craters then stands to reason why I struggled make out the concentric structure of Pontamus E below 110X. Most likely tomorrow night the shadows may be already too short to make out the concentric structure. One, two and no more than three days out from the terminator is optimal to view these.
No sketch tonight though <sigh> - way too dewy here at home as this will stuff the paper. Seeing was pretty good too, but no cigar tonight.
Alex.