Running north from the crater Birt and parallel with Rupes Recta the Straight Wall, is a cleft called Rima Birt that is supposed to be visible in larger telescopes according to Rukl's. I can see it with the Club 6", barely with 90x and definitely at 250x. Very very fine. The cleft and the wall both end simultaneously at their north ends. John Holmquist knew how to grind a mirror. Jack Jones Saguaro Astronomy Club Lunar List Awards and Messier Marathon Co-coordinator Phoenix AZ spicastar@xxxxxxxxxxxxxxx > > Looks like the peak of Montes Recti, "behind" > Montes Teneriffe, is emerging from > shadow. Just the tip is visible right now. > > Matt -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list.