FEB 28TH TONIGHT ONLY - BARKERS QUADRANGLE ON THE MOON

[paulastro]

Here's a challenge from Nigel Longshaw in Feb's AN.

Id noted it in my diary as something to look for if it was clear tonight - and it looks like it might be.

I didnt know about it before I read Nigel's article. Hopefully others may find it of interest too.

 

[Mark at Beaufort]

Paul this is an interesting one. The quad does not appear in the 21st Century atlas - well I can't see it!!

Anyway I thought I would check out my Moon Maps by H.P. Wilkins which I bought about 55 years ago. Here is a copy from the area. The quad appears to be marked 'x' - am I correct do you think?

This book is a first edition and cost me 30s

[paulastro]

Mark, I've had a careful look, and I cant see the x you are talking about.  There is so much detail,  it's rather confusing.  I'm presuming the map is orientated inverted?  I didnt see Dorsa Harker on the map, but then it may not have been included.

I have seen some information on the feature in Lunar Cognitta but I cant remember where.

I think if the lighting is correct, it wont be too difficult to see. Nigel was only using a 76mm refractor, though he does have an excellent eye and is a top notch observer.

[Mark at Beaufort]

Paul the x is at 10 o'clock with Pichard at the centre. The x is also left on a straight line from Lick crater. I will have a go tonight using the 130 heritage.

 

[Laurieast]

Edited February 28, 2021 by Laurieast

[paulastro]

Thanks Mark and Laurie, its certainly close to where it should be, and looks like it. Its very interesting if Willkins observed and recorded it on his map.  I've looked in several photographic resources and not seen it represented.  

However this isnt too surprising perhaps.   Lunar observers know very well that effects of the changing sun angle on the Moon can cause features to change their appearance very rapidly.  In this respects visual observers have an advantage over imagers.  The latter may take a pic in a fraction of a second, and may not look at the feature long enough to observe how it changes.

 

[Sky-searcher]

2 hours ago, paulastro said:

Here's a challenge from Nigel Longshaw in Feb's AN.

Id noted it in my diary as something to look for if it was clear tonight - and it looks like it might be.

I didnt know about it before I read Nigel's article. Hopefully others may find it of interest too.

I was all set to have a go tonight after reading earlier & we had clear skies, but now fog has quickly moved in here spoiling my evening

[Stu]

All interesting stuff! Thanks Paul, might pop the Heritage 150p out for a quick look. Can’t be up late though ‘school night’ tonight  

[mikeDnight]

1 hour ago, Laurieast said:

To add a little more info about Barkers Quadrangle, Wilkins makes a comment in his book The Moon (Wilkins & Moore). Page 197 paragraph 5. [It might be worth noting that since Wilkins wrote his book, the east west has changed, so that Wilkins west is now IAU east. If you could stand on the Moon with your back to north, the east would be to your left and west to your right, just as it would be on earth].

Edited February 28, 2021 by mikeDnight

[Stu]

Success here I believe. I certainly saw a rectangular shape with four corners. Managed to take a picture which I think shows it. Clearer visually of course.

Thanks @paulastrofor the heads up. Gave me a reason to get out with the Heritage 150P

[Mark at Beaufort]

I had a session with the Heritage 130p after the SGL zoom meeting. Whereas I could pick up quite a bit of detail I could not see the Quad. I was using a baader 2.25x Barlow and a 9mm Fujiyama Ortho.

 

[John]

18 minutes ago, Stu said:

Success here I believe. I certainly saw a rectangular shape with four corners. Managed to take a picture which I think shows it. Clearer visually of course.

Thanks @paulastrofor the heads up. Gave me a reason to get out with the Heritage 150P

I'm just observing that very feature now with my Tak FC100 at 257x. Not quite a perfect rectangle, slightly rhomboid on one of the shorter sides but it is pretty clearly defined. Now whether that is because of Paul's "heads up" and / or Stu's image and I'm looking for it, I'm not sure 

The "lines" between the corners are pretty fine - probably just a small change in illumination will impact them.

Nice image Stu and thanks for the tip to watch out for this Paul

 

 

Edited February 28, 2021 by John

[Stu]

19 minutes ago, John said:

I'm just observing that very feature now with my Tak FC100 at 257x. Not quite a perfect rectangle, slightly rhomboid on one of the shorter sides but it is pretty clearly defined. Now whether that is because of Paul's "heads up" and / or Stu's image and I'm looking for it, I'm not sure 

The "lines" between the corners are pretty fine - probably just a small change in illumination will impact them.

Nice image Stu and thanks for the tip to watch out for this Paul

 

 

Good stuff John. It did seem quite clear here which was great. I used a Nag zoom in the Heritage which gives x250 at max zoom, so quite similar to you.

I processed another image to show it more clearly, attached here.

[mikeDnight]

I'm pretty certain that rectangle isn't it.  Between the rectangle and Picard is a diamond, or kite shape, somewhat more subdued and having more of a trapezium shape. It seems to be composed of wrinkle ridges that have small craterlets at at least two, possibly three of its corners. There's a long wrinkle ridge extending from one corner giving it a kite tail appearance. There's also a fine ridge or possibly a rille crossing from the corner crater across its centre towards the corner with the kite tail, but I don't think it makes the whole distance.  I was observing around 2200UT, using my 4" OG with barlowed binoviewer and 35mm Ultima 's, ~90X. Seeing was wobbly but got a little steadier as time went on. 

All in all it was pretty uninspiring, but I did catch sight of a fine rille near to the western shore of Crisium that I've never seen before.

Edited February 28, 2021 by mikeDnight

[AstroTim]

Thanks @paulastro. I’ve enjoyed looking for the unusual features you have highlighted over the last couple of nights. It’s got me out observing on at least one night I wouldn’t have otherwise tried, and I’ve seen some new features that I probably wouldn’t have ever known about otherwise.

Also thanks to everyone else who has chipped in with maps, diagrams, and other noteworthy features nearby.

Tim

[John]

I'll have another look Mike

I got distracted by Petavius and Langrenus both of which are spectacular tonight. The shadows of the central peaks in Langrenus and the shadows on it's ramparts remind me of a Chesley Bonestell painting

[John]

2 minutes ago, John said:

I'll have another look Mike

I got distracted by Petavius and Langrenus both of which are spectacular tonight. The shadows of the central peaks in Langrenus and the shadows on it's ramparts remind me of a Chesley Bonestell painting

Ahh - I see the "kite" shape and it's tail now.

Trouble is, as you start to look hard, the illuminated wrinkle ridges across the mare floor can start to look like all sorts of things

[AstroTim]

@Stu your second image shows what I thought was Barkers Quadrangle with a prominent line leading from it. I think that matches the kite shape that @mikeDnight mentions also.

Tim

 

[John]

I've been reading through a CN forum thread on this topic from 2010. This post:

https://www.cloudynights.com/topic/281631-barkers-quadrangle-location/?p=3600170

includes an extract from Sir Patrick Moore's book "Survey of the Moon" and an image similar to @Stu's which seems to suggest what and where this mysterious feature might be.

I'm going to pack in tonight I think but it's been an interesting "quest"

[AstroTim]

So, possibly not where the X was on the map, but the feature next to it. Fortunately I did spend quite some time looking at that  area too 

 

Edited March 1, 2021 by AstroTim

[mikeDnight]

Hmm.  Referring back to Wilkins notes above, he refers to Barker being the first to trace this diamond shaped feature, yet looking back at the snippet posted at the start, it appears the rectangular form is where it is. So Stu was right! 

Still, I saw Barkers quadrangle and as a bonus, spent ages studying the neighbouring diamond noted by wilkins, and marked as X on wilkins chart.  That was more of a challenge, but in studying it I saw things I wouldn't normally have seen.  

[John]

3 hours ago, mikeDnight said:

..... in studying it I saw things I wouldn't normally have seen.  

And there's the joy of it

[paulastro]

I' m pleased this generated some interest  - and observing!  Alas, I wasn't very well yesterd evening so couldnt observe. Still, great to read about other folk's adventures.

The good thing is, there's another opportunity post-midnight on March 29th/30th .  I'll post a reminder nearer the time.

Edited March 1, 2021 by paulastro

[Stu]

28 minutes ago, paulastro said:

I'll post a reminder nearer the time.

Maybe pop it in the Heads up section and calendar Paul, so we all get a reminder?

Hope you feel better soon!

[mikeDnight]

2 hours ago, John said:

And there's the joy of it

Absolutely!   And to finish the evening off I had a beautiful view of the Beehive through my 35mm Ultima (gorgeous), and a really nice view of shrinking Mars through my binoviewer. At first glance Mars looked like a tiny gibbous, with a dark smudge in the centre of its disc. But after only a few minutes, that dark smudge began to show subtle variations in darkness, and had narrow dark arms extending from it, the longest of which I imagine may have been sinus Sabaeus. Syrtis M was likely off centre at around 22.15UT, but I haven't checked the LCM, and didn't make a sketch.