Hadley Rille with FC100DC

[MalcolmM]

I was going to post last night asking if the Hadley Rille was possible in a 4" refractor. I tried for half an hour, the sky was clear but the seeing was unsteady and while Hadley was pretty easy there was no sign of the Rille.

The clouds were out tonight but in-between there were clear bits and I took my 60CB out to check the seeing. In-between the clouds the seeing looked rock steady so I thought I'd give it another go.

So I brought out the 100DC on a Giro Ercole and battling the odd gust that shook the scope, the clouds that only gave me glimpses and nudging the scope manually I thought I could see it with a Nagler zoom on 3mm. Really excited now and thinking the conditions could allow more magnification I put in the Tak TOE 2.5mm and it was really quite obvious. I have attached a shocking sketch (not easy I find in the best conditions let alone shifting cloud and nudging scope!). It was more of a curving light streak rather than the dark one in my sketch but hopefully it has enough detail that someone can confirm it's the Rille. I could only see it on one side of Hadley but I had read you needed an 8" scope to see it and someone else said they had seen it in a 5" refractor.

A very excited,

Malcolm

 

[John]

Nice report and sketch

The seeing tonight is really excellent - fine features on the moon (eg: Hadley Rille) are standing out as well as I've seen them for quite a while.

 

[Mr Spock]

Nice one. I didn't get that far - it's that "there's too much to see" thing again. Next time maybe.

Seeing was decent earlier with my 102mm holding x292 really well. It's gone really poor now though. Shame as we haven't had many nights as clear as this for a while.

[JeremyS]

Great report @MalcolmM 👍🏻

[JAC51]

I think you have seen the Hadley Rille it’s quite possible for a small telescope to resolve the length of the rille if not its width rather like the the Cassini division in Saturns  rings. I have see the Rille in a 5” refractor and posted my poor drawings on CN a few years ago. I will try and find my sketch’s tomorrow and post them so you can compare them to yours. I wondering what actually is the smallest aperture the rille can be seen with?

[John]

I've seen the Hadley rille with my 100mm refractor. Tonight some sections of it were clear with my 120mm.

I snapped an image of it a while back with my mobile phone at the eyepiece of my 12 inch dobsonian. Not the best clarity but at least the rille can be seen !

 

 

[BRADLEY 1953]

Yes, I agree, seeing was surprisingly steady tonight and great details on view. I had a wonderful tour of the morning terminator through my 130mm APO, Copernicus nearby truly outstanding.   Happy new year to everyone  (belated). 

[MalcolmM]

7 hours ago, John said:

I snapped an image of it a while back with my mobile phone at the eyepiece of my 12 inch dobsonian

That's a great image. The visual view must have been stunning. What atlas is that @John? I'm on the lookout for something a little more detailed for lunar observing than Turn Left at Orion.

Thanks,

Malcolm

[Nik271]

This chart seems to be based on the LAC series produced for USAF for the Apollo moon landings from observations and photographs. They have a very classic look similar to a geography atlas with altitude contours. In this age of satellite imagery they have a very different look. I like them a lot actually.

They are available for free here: https://www.lpi.usra.edu/resources/mapcatalog/LAC/

I printed them out and bound them in an A3 atlas. A bit bulky for the observing session but wonderful to browse and plan on a rainy day.

 

[John]

8 hours ago, MalcolmM said:

That's a great image. The visual view must have been stunning. What atlas is that @John? I'm on the lookout for something a little more detailed for lunar observing than Turn Left at Orion.

Thanks,

Malcolm

Sorry - I missed your question.

The map is an extract of the ones that Nik mentions above, that I picked up online.

I mostly use the 21st Century Atlas of the Moon by Wood and Collins plus the freeware Virtual Moon Atlas plus a couple of free Android apps.

 

[Stu]

17 hours ago, MalcolmM said:

I was going to post last night asking if the Hadley Rille was possible in a 4" refractor. I tried for half an hour, the sky was clear but the seeing was unsteady and while Hadley was pretty easy there was no sign of the Rille.

The clouds were out tonight but in-between there were clear bits and I took my 60CB out to check the seeing. In-between the clouds the seeing looked rock steady so I thought I'd give it another go.

So I brought out the 100DC on a Giro Ercole and battling the odd gust that shook the scope, the clouds that only gave me glimpses and nudging the scope manually I thought I could see it with a Nagler zoom on 3mm. Really excited now and thinking the conditions could allow more magnification I put in the Tak TOE 2.5mm and it was really quite obvious. I have attached a shocking sketch (not easy I find in the best conditions let alone shifting cloud and nudging scope!). It was more of a curving light streak rather than the dark one in my sketch but hopefully it has enough detail that someone can confirm it's the Rille. I could only see it on one side of Hadley but I had read you needed an 8" scope to see it and someone else said they had seen it in a 5" refractor.

A very excited,

Malcolm

 

Hi Malcolm, from your sketch I think you saw the bright curve at the end of it, but didn’t resolve the sinuous, winding part which I think of as the Rille proper. It’s a tough target and needs good seeing and the correct illumination. Not sure if I’ve seen it in a 4” before, certainly in my 8” f8, and last night I saw parts of it in the 130mm but not all.

I’ve inverted and reversed your sketch so it matches a couple of screenshots I took from Lunar Quickmap, which is an excellent site for checking out fine details and features.

https://quickmap.lroc.asu.edu/?extent=-90,-62.8121931,90,62.8121931&proj=10&layers=NrBsFYBoAZIRnpEBmZcAsjYIHYFcAbAyAbwF8BdC0yioA

There is also the NASA lunar simulator which is great for simulating the terminator and conditions for any phase, but not so good with labelling features.

https://svs.gsfc.nasa.gov/4955

Hope that helps a little?

 

[Stu]

I just dug out this old report which indicates that I have not managed to see it all in my FC100DC, and that the 8” f8 has given me my best views.

[Deadlake]

15 minutes ago, Stu said:

I just dug out this old report which indicates that I have not managed to see it all in my FC100DC, and that the 8” f8 has given me my best views.

Maybe your 5" will work? Not that you need an excuse. Have you got around to trying out your TOE 3.3 mm on it?

[MalcolmM]

@Nik271, @John & @Stu thank you all very much for the useful information.

I'll check out the lunar on-line resources.

I have been hovering over the buy button for the Wood & Collins atlas on Amazon for a few days!

And Stu, I think you have nailed what I saw. The seeing was very good for me last night with a 2.5mm TOE so I probably will not be able to see any more detail on the Rille ... but I'll keep trying

Thanks again,

Malcolm

[Mr Spock]

Not something I've gone looking for tbh. I'll give it a go with the 10" dob the next favourable illumination.

[JAC51]

Here is a copy of what I posted on CN, two years ago. Please forgive the poor drawing, in particular  all the surrounding features are slightly spaced out compared two the size of the Rille in my drawing. Also the rille as I saw it was a very fine light grey ribbon, thread like, extending above and below the small crater. The southern end of the ribbon became a brighter curve which I thought at the time was the slope of a hill.

[John]

With fine features such as rilles and craterlets, the lunar illumination can be critical in determining what you see and the extent of it. 

Sometimes the optimum time window is just a few hours during which the solar illumination falls favourably.

Add to that the need for steady seeing to pick up the finer details and it's clear why sometimes things just don't quite work out.

At least with the moon, if you don't get it this time, there is always another chance in just under a month.

 

 

 

Edited January 14, 2022 by John

[mikeDnight]

I've seen it in my FC100DC and found it easy, but I suspect much depends on the illumination and seeing conditions. I should add that I almost always use a binoviewer for observing the Moon, and that makes seeing fine linear features less challenging. 

Edited January 15, 2022 by mikeDnight