John

Thank you Stu And there it was, gone !

Thanks for the feedback folks Last nights observing prompted me to have a look through some Apollo 15 mission information. Amazing to think that it all happened 50 years ago this year. I was 11 years old and very heavily influenced by the Apollo programme which is why I guess I'm here now I'd forgotten that this was the mission which included the hammer vs feather experiment: https://solarsystem.nasa.gov/resources/329/the-apollo-15-hammer-feather-drop/

You were the Science Officer Mr Spock - did you try and dissuade Kirk from this damaging activity ?

If it's any consolation to those who didn't manage to see this rille, my seeing conditions here were excellent but even so it was a very challenging thing to see even with my 12 inch dob which has very good optics and is well collimated. It was not visible consistently by any means and even when it was, I just got glimpses of a few sections of the rille. Plus I've seen it before with this scope, and that helps a lot ! I've not seen the rille with any of my smaller aperture scopes which include some pretty good refractors to 130mm in aperture. As well as the really excellent scope and, obviously tonight, seeing conditions, mikeDnight possesses visual acuity well beyond mine I'm sure to get this with 100mm of aperture Great observing Mike

I didn't notice this myself Stu but I was concentrating on the area where the rille goes around the foot of the Mons Hadley rather than the flat plain where the LEM touched down. You might have seen shadows caused by either the North Complex or South Cluster formations which are a few km either side of the landing site ?

I think that is very true, especially with these very fine details. Even the change in illumination over a few hours can make a difference. I believe that this rille is only 1km wide at maximum, less for most of it's length, and only 240m deep at the deepest point.

Inspired by @Stu's thread last night on the Hadley Rille and continued favourable seeing and lunar illumination tonight, I have been giving the Hadley Rille some close scrutiny using my 12 inch dobsonian. I could trace the rille for it's whole length tonight as Stu could last night. This is his thread: https://stargazerslounge.com/topic/376134-hadley-rille-looking-fantastic-20th-april-2020/?tab=comments#comment-4076070 The area surrounding the Apollo 15 landing site was very nicely illuminated and, for the first time that I can recall, I could make out the crater St George on the western facing slopes of the Mons Hadley Delta overlooking a meander of the Hadley Rille. The ejected material surrounding St George crater was visited and sampled by James Irwin and David Scott in the Lunar Roving Vehicle. The crater is 2.42km in diameter and lies 4km south west from the Apollo 15 landing site. This was a nice spot and showed how steady the seeing was tonight, in between puffs of wind. I was using 338x magnification. St George is behind James Irwin as he loads up the LRV in this photo:

Very fine looking scope Piero

Hadley Rille is looking lovely tonight as well

Yes I can see it Mike. But I am using my 12 inch dob

Moon in the sights of the 12 inch dob:

I've probably posted these before but never mind. TMB/LZOS triplet 130mm F/9.3 on the T-Rex alt-azimuth mount:

I saw those last night. There was also a thin rille visible that runs past the pair of spots in the top right of the crater in your photo.

I've not found such a difference between my ED120 and my FC100 DL. There have been a number of occasions when the additional aperture has delivered something that the 100mm could not. That's why I still have the ED120

I do find my lunar observing has been made much more interesting by the "21st Century Atlas of the Moon" by Charles Wood and Maurice Collins What I love about that book is that it invites the amateur observer to ask questions and to share in trying work out what might have been going on to create the features we see. Whereas many astronomy books will state something like "this feature is caused by factors X and Y" the 12st Century Atlas is open about the perplexities that face lunar scientists in many cases - why are there dark patches in this crater but not in the one next door ?, why has rille x taken a sharp deviation at this point ?, scientists are divided on whether such and such a feature is of volcanic or impact origin, or maybe both ?, is it a co-incidence that this feature lies in an area of some of the strongest magnetic anomolies ? Once you start thinking this way I think you start observing (rather than just looking perhaps ?) questioning what you are seeing and then go seeking other examples of your own I've been trying this approach on non-lunar observing as well over the past year or so and often find that it does add a further dimension to familiar targets as well as new ones It's working for me anyway

Interesting ! The Rima Birt was very well defined with my Skywatcher ED120 this evening. I would imagine that the Edge 8 ought to beat it though

Great report Stu ! Those catenas / crater chains are great - the one across Davy is very delicate and there are some others not far away as well. I was impressed by the sharpness and clarity of the moon tonight, despite the thin high cloud. I was pleased to see the rille across the floor of Alphonsus tonight and also the dome next to Gambart C as well as a myriad of other detail.

100mm is the smallest aperture for me. I have owned a number of decent 70, 80 and 90mm refractors but didn't hang onto them for too long.

I've packed in as well now. Too much cloud cover for other targets. Great stuff on the moon though

Luckily, you already have an excellent refractor - your Skywatcher ED120

The thin cloud is a bit thicker here as well now but the moon is still showing well. Not many stars to be seen though ! I'm mostly using 191x with the ED120 currently. That seems to give a very sharp and contrasty view despite the thin cloud cover.

Excellent illumination for the rille and the Apennines tonight Further south, the crater Alpetragius just N of the Straight Wall is really well illuminated as well. It has that huge, egg-like, central mountain / bulge in it's centre. Very striking !

Not a strict one but they all get used quite often. The 12 inch dob and the Tak 100 are probably the most used though. The Vixen 102 perhaps the least and about "honours even" between the ED120 and the TMB/LZOS 130. If I ever wanted to reduce the number of scopes I own (and it has crossed my mind a few times) I would find it difficult to make the decision on which to part with. They each have characteristics that I'm very fond of

The old ED120 is out this evening. Very nice lunar views. Thin high clouds here will probably not help deep sky stuff. Maybe some double stars later though ?

A simple rig and another with the moon in the eyepiece this evening The seeing is superb just now.