With a 6" the seeing definitely has to settle and you have to 'stare' for a while. You are right, the cleft terminates at Birt 'E' and widens out there, at least according to the Rukl drawing. Jack Jones Saguaro Astronomy Club Lunar List Awards and Messier Marathon Co-coordinator Phoenix AZ spicastar@xxxxxxxxxxxxxxx > > Jack, > > I can make out only the north end of this feature, and then > only when the seeing settles. It seems to terminate at a > small crater. This is with my 120mm at 227x. > > Matt -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list.