Lunar Crack with the Big Mak!

[Nightspore]

Last night I managed to get the ‘Big Mak’ out for the first time this year. Some people regularly inform me that at 127mm it isn’t really that big. Although it’s what you do with it that counts, right? Besides, it’s the biggest Maksutov telescope I own. 

 

Big Mak cooling on a Vixen Porta II/TL-130 with a Baader Zeiss specification Amici and newly added reflex sight

 

I set-up at twilight around 19:45 BST. The enclosed system of the ‘Big Mak’ can take up to an hour to reach thermal equilibrium. The Moon was at about 58° in altitude and would descend to around 49° by 21:00. It was 36.3% illuminated and almost thirty arc minutes in apparent size. The seeing and transparency were about average, albeit a little humid. My original intention was to take out only one eyepiece; an 8-24mm Celestron zoom. This was fundamentally to save weight and space when transporting the entire ensemble down the garden. However, I couldn’t resist taking a fistful of Plossls out with me. Or rather more accurately three of my old Omni Plossls of 15mm, 12mm and 6mm (now with GSO barrels) accompanied by 9mm and 20mm Bresser five element 60° ‘Plossls’. This collection was topped off with four Wratten (# 8, 12, 15, 21) filters. Along with the Baader Neodymium and Baader Single Polarising filters that regularly accompany me on nocturnal excursions.

 

 

At 20:30 I decided the tube had cooled sufficiently to try the 20mm Bresser for 77x. This gave approximately forty seven arc minutes of field and I could see the entirety of the lunar disc in the eyepiece view. As it seemed relatively clear with adequate visual acuity I increased the magnification. Initially to 103x, and then 128x with the 15mm and 12mm Celestron Plossls respectively. 

 

SkySafari 6 Pro on Android

 

I could not see the floor of either of the Aristotles and Eudoxus features. The bottom of the craters were shrouded in darkness as a consequence of being too near the terminator. The ninety five kilometre Posidonius impact crater was particularly well illuminated and warranted further magnification. Its seventy eight kilometre rimae (fissure) and adjacent crater were astonishingly revealed. What fascinated me the most however were the intricate and intriguing shadow details around the crater rim itself. This terminator chiaroscuro dramatically highlighted the escarpment area around the rim of Posidonius. Which prompted me to increase the magnification to 171x with the 9mm Bresser and then ultimately to 257x with the 6mm Omni. I switched to the Celestron zoom and moving back and forth between 128x and 192.5x I was getting a nice ‘butcher’s hook’ at the Dorsum Buckland. An elevated ridge area north west of the Plinius crater. I could also easily view one of my favourite linked trio of craters, now enticingly near the terminator. These are situated just to the south of the two hundred kilometre Sinus Asperitatus region. Theophilus, Cyrillus and Catherina are all possible impact craters between ninety eight and ninety nine kilometres wide. There has been some conjecture that one or more of them are volcanic in origin. 

 

Moon Atlas on macOS (Theophilus, Cyrillus and Catherina can be seen immediately to the left of the Mare Nectaris)

 

The two kilometre high triple-peaked central mountain of Theophilus was very distinct and its crater walls were very nicely defined with a great deal of detail. The floor of the adjoining Cyrillus and its satellite crater ‘Cyrillus A’ within it were easily perceived. Catherina’s highly irregular rim was well in evidence as were the ‘Catherina P’ and ‘Catherina S’ depressions in the crater floor. Other notable features were the Mare Nectaris, Piccolomini, and Janssen with its distinctive rimae. After two hours and forty minutes it was getting damp and cold. I finished the session feeling quite confident that I’d had a good crack at the Moon with the Big Mak.

 

Edited April 8, 2022 by Nightspore

[+Streetbob]

I think you can safely say that was a 'fair old crack' at the moon.

[+Glafnazur]

Great report, almost feels like I was there 🙂 

 

I had to google 'chiaroscuro' 

[Nightspore]

12 minutes ago, Glafnazur said:

Great report, almost feels like I was there 🙂 

 

I had to google 'chiaroscuro' 

 

Thanks. The session turned out better than I thought it would. It's been a cold April. You can tell I studied some art history lol.

[+Bino-viewer]

I had to look it up too.....!! 😀

 

Despite having an Italian brother in law my knowledge of the language is practically non existent.

 

A good read, and you set the bar pretty high with Lunar observation, and knowledge of what you are looking at.

I wish mine was half as good.

 

Have you considered insulating your Mak scope ?

Theres quite a growing number of observers, both with Maks and SCTs that use a material called 'Reflectix' - basically a padded foil wrap

that is often used behind radiators to insulate these scopes and lessen thermal issues. I'm not sure if anyone on here has tried it though. But just a thought.

 

I was also looking a few days ago at a Mak scope myself.

A used Meade ETX 105. One of the American ones.

I'm not sure if it was a de-forked scope of if it was one of the OTA versions. They did make a few like this and are quite rare.

I've never owned a Mak scope and i was a bit intrigued. It was £150 and fairly local. But i didn't make any direct enquiries. Perhaps i should have done ?

 

 

 

[+Glafnazur]

15 minutes ago, Bino-viewer said:

I was also looking a few days ago at a Mak scope myself.

A used Meade ETX 105. One of the American ones.

I'm not sure if it was a de-forked scope of if it was one of the OTA versions. They did make a few like this and are quite rare.

I've never owned a Mak scope and i was a bit intrigued. It was £150 and fairly local. But i didn't make any direct enquiries. Perhaps i should have done ?

 

 

 

I've got the Bresser 127 and it is a lovely scope but I really don't like the focuser knob, I am thinking of replacing it with a Crayford focuser. I sent an email to FLO and they've not got anything but suggested https://www.teleskop-express.de/shop/product_info.php/language/en/info/p11734_TS-Optics-1-25----T2-Crayford-Focuser-for-Refractors--Cassegrains-----.html with https://www.teleskop-express.de/shop/product_info.php/language/en/info/p11734_TS-Optics-1-25----T2-Crayford-Focuser-for-Refractors--Cassegrains-----.html but at the moment it has an unknown waiting time.

 

Ages back I had a Meade 125, and again it was a very nice scope but I sold it on as I didn't like the focuser knob. Maybe I just need to use the Mak more and get used to it?

Edited April 8, 2022 by Glafnazur
Typo

[Nightspore]

1 hour ago, Bino-viewer said:

I had to look it up too.....!! 😀

 

Despite having an Italian brother in law my knowledge of the language is practically non existent.

 

A good read, and you set the bar pretty high with Lunar observation, and knowledge of what you are looking at.

I wish mine was half as good.

 

Have you considered insulating your Mak scope ?

Theres quite a growing number of observers, both with Maks and SCTs that use a material called 'Reflectix' - basically a padded foil wrap

that is often used behind radiators to insulate these scopes and lessen thermal issues. I'm not sure if anyone on here has tried it though. But just a thought.

 

I was also looking a few days ago at a Mak scope myself.

A used Meade ETX 105. One of the American ones.

I'm not sure if it was a de-forked scope of if it was one of the OTA versions. They did make a few like this and are quite rare.

I've never owned a Mak scope and i was a bit intrigued. It was £150 and fairly local. But i didn't make any direct enquiries. Perhaps i should have done ?

 

 

 

 

Thanks, I've always enjoyed a bit of Moon bothering lol. I have heard of these insulating materials, although I thought it was a bit of a DIY fad or something. I don't know about the Meade MCT's but they have a good reputation.

 

IME Mak's can be a bit limited. Rich field is difficult as they are pretty slow scopes. Only brighter DSO's are easy to see. There's the lengthy cool down time. Doubles aren't easy as the Gregory spot tends to make the first diffraction ring bright. So close doubles take some effort. At 127mm and over they can suffer from 'mirror flop' as focus is achieved by moving the mirror itself.

 

 

The upside is that you can put a 5" scope into a bag this small and there is no discernible CA.

[Nightspore]

1 hour ago, Glafnazur said:

I've got the Bresser 127 and it is a lovely scope but I really don't like the focuser knob, I am thinking of replacing it with a Crayford focuser. I sent an email to FLO and they've not got anything but suggested https://www.teleskop-express.de/shop/product_info.php/language/en/info/p11734_TS-Optics-1-25----T2-Crayford-Focuser-for-Refractors--Cassegrains-----.html with https://www.teleskop-express.de/shop/product_info.php/language/en/info/p11734_TS-Optics-1-25----T2-Crayford-Focuser-for-Refractors--Cassegrains-----.html but at the moment it has an unknown waiting time.

 

Ages back I had a Meade 125, and again it was a very nice scope but I sold it on as I didn't like the focuser knob. Maybe I just need to use the Mak more and get used to it?

 

I think most Mak focusers are a bit weird. This is the reason I tend to use diagonals with helical focusers with them.

 

[Nightspore]

 

On Saturday teatime I had my usual weekend fish and chips and was correspondingly full of beans. Well, full of lightly battered cod and chips. That is, of course, assuming it was not Vietnamese catfish masquerading as the benthopelagic Gadus morhua. So suitably energised by all the protein and carbohydrates I decided to set the Big Mak up again. I took the same eyepieces out as Friday, except this time I took some Baader colour filters and a Lumicon #11 Yellow-Green. The First Quarter Moon was unmistakably in Gemini, at an altitude of nearly 62° and 55.2% illuminated. At 20:30 the 127mm catadioptric had cooled sufficiently to attempt some viewing. As usual I started off at 77x and 103x. The seeing and transparency appeared above average. As the sky was still a bit blue I used the Baader 495nm yellow longpass filter for a tad more contrast. In fact, I used this particular filter for virtually the entirety of the session. I’d totally forgotten just how effective it was.

 

 

Starting in the northern hemisphere I was very impressed with the jagged crater wall shadows on the eastern floor of Archimedes. The largest impact crater (eighty one kilometres) on the Mare Imbrium. The nearby Aristillus crater’s ejecta ray system was prevalent but it was the central peaks, nearly a kilometre high, that really caught my attention.
 

 

The Mons Bradley massif, named after the English astronomer James Bradley (1692-1762), was very nicely illuminated. Situated in the Montes Apenninus it is over four kilometres high. Although I could easily see the nearby Conon crater, the fifty nine kilometre Eratosthenes impact crater was mostly obscured by terminator shadow. Baron von Gruithuisen’s ‘lunar city’ was nicely highlighted. No sign of his giant moon fleas though! The almost perfectly circular one hundred and fifty four kilometre Ptolemaeus depression is usually best observed at quarter phase. It didn’t let me down and the internal Ammonius impact crater was nicely contrasted.

 

 

I find Ptolemaeus eminently useful for locating the Rupes Recta. A one hundred and ten kilometre escarpment or linear fault. It is actually shallower than it appears, but when it is sufficiently near the terminator it is fabulously and dramatically contrasted against the cycloramic backdrop of the Mare Nubium. This was in fact my ‘target for tonight’. I certainly wasn’t disappointed and managed 192.5x and 257x on it for a while. Eventually around 22:00 a blanket of very white cloud came out of the west and ended the session.

Screenshots by courtesy of Stellarium and SkySafari Pro

[+Glafnazur]

Sounds like another good session. I got the Bresser 127 Mak out last night and had my best session with it. I finally managed to get my WO binoviewers to focus and the moon looked fantastic. Reading your reports has made me want to spend more time observing the moon and identifying it's surface features. It is an object that have given very little attention to over the years, just a quick look every now and again. I've probably cursed it for drowning out DSOs more times than I've observed it.

[+Streetbob]

I joined you with my Starwave 102 frac. I used my ES 18mm & 11mm ep and an Altair 15mm UF (my ep of choice). The Alpenninus and Alpha really stood out for me. 

25 minutes ago, Glafnazur said:

Reading your reports has made me want to spend more time observing the moon and identifying it's surface features.

I agree Dave as the light pollution has got so bad here now the moon is still something I can observe.

 

2 hours ago, Nightspore said:

Baron von Gruithuisen’s ‘lunar city’ was nicely highlighted. No sign of his giant moon fleas though!

I think you need a few more beers with your fish & chips before you start seeing giant moon fleas. 
Thanks for your report.

[Nightspore]

1 hour ago, Glafnazur said:

Sounds like another good session. I got the Bresser 127 Mak out last night and had my best session with it. I finally managed to get my WO binoviewers to focus and the moon looked fantastic. Reading your reports has made me want to spend more time observing the moon and identifying it's surface features. It is an object that have given very little attention to over the years, just a quick look every now and again. I've probably cursed it for drowning out DSOs more times than I've observed it.

 

It was pretty good, although I would have liked longer. I was seriously considering using my WO's, they are great for the Moon. I feel like an Apollo astronaut when I'm using them lol. 

 

 

 

[Nightspore]

39 minutes ago, Streetbob said:

I joined you with my Starwave 102 frac. I used my ES 18mm & 11mm ep and an Altair 15mm UF (my ep of choice). The Alpenninus and Alpha really stood out for me. 

 

 

I think you need a few more beers with your fish & chips before you start seeing giant moon fleas. 
Thanks for your report.

 

You're welcome. I have the same frac and it is very good for the Moon. I don't know what Gruithuisen was drinking. I just think he hadn't cleaned his scope for a while lol.

 

 

[Nightspore]

A head's up for Schroter's Valley being near the terminator on Wednesday night. 

 

[+Streetbob]

On 10/04/2022 at 18:52, Nightspore said:

A head's up for Schroter's Valley being near the terminator on Wednesday night. 

I spent a most enjoyable couple of hours on the moon last night. I was particularly looking for Schroter’s Valley. I had good views even with a ES 6.7mm which gives  mag of 112.  Also had a good study all along the terminator. Thanks for the heads up.

[Nightspore]

7 hours ago, Streetbob said:

I spent a most enjoyable couple of hours on the moon last night. I was particularly looking for Schroter’s Valley. I had good views even with a ES 6.7mm which gives  mag of 112.  Also had a good study all along the terminator. Thanks for the heads up.

 

I'm glad you had a good one. It was pretty good for me too. I watched the Moon almost three hours until transit (23:01) and at times got 257x. Although I mostly just used Plossls.

[Nightspore]

On Wednesday the 13th of April at 20:30 BST the Big Mak had been cooling for thirty minutes. The Moon was in Leo and about 37° in altitude. It was 89.7% illuminated and would reach transit at 23:01 BST. I decided on an initial observation with Baader Red 610 nm and Orange 570 nm longpass filters. The conditions were generally above average although it was fairly humid. There was some slight atmospheric ‘boiling’ perceptible around the limb. I assumed this would dissipate as the Moon rose higher. At transit it would be at a very congenial 46° in altitude.

 

 

The Mare Imbrium displayed some engaging detail and the Montes Recti were clearly delineated. Mons Pico was bright but not too well defined. To the east there was detail in Copernicus even though it was some distance from the terminator. Aristarchus and the surrounding region looked very promising. The nearby valley area was wonderfully highlighted. The Gassendi crater was conspicuously distinct as it nestled just inside the twenty six hundred kilometre Oceanus Procellarum.

 

 

Further south the Schickard crater was marvellously displayed and it was just touching the tenebrous side of the terminator. Schickard actually appears as an elliptical shape through the eyepiece due to the foreshortening effect. Eventually I increased the magnifications to between 125x and 257x. I used three more filters in succession, this time predominantly threaded into the Baader Amici prism nosepiece. I find that there is less chance of the filter dewing over in the relatively insulated back of a catadioptric, especially compared to a refractor visual back. Most of the session was now conducted with the Baader Yellow 495 nm longpass and predominantly between around 154x and 171x. Although I did occasionally use the Baader Contrast Booster, Light Blue 470 nm bandpass and Lumicon #11 Yellow-Green filters. 

 

 

I spent some time in the Montes Jura and the surrounding area before inevitably travelling south towards the ninety three kilometre wide Montes Harbinger. So called as they appear to harbinger the dawn on the nearby Aristarchus crater. The detail in the terraced outer wall of the crater itself was considerable. Aristarchus reputedly has an albedo twice as bright as that of any comparable lunar feature. I was delighted, and slightly surprised, to observe sunlight glinting on its multiple central peaks. This was peculiarly juxtaposed with the flat, gloomy, and caliginous frozen lava floor of the adjacent Herodotus crater. The Vallis Schroteri is the largest sinuous rille on the Moon. I saw excellent detail in the pyroclastic flow areas up to and including a good 257x magnification with a 6mm Plossl and the Lumicon #11. 

 

 

Further south I had a sublime view of the ‘diamond ring’ formed by the large impact crater Gassendi and its smaller satellite Gassendi ‘A’ (the diamond). Although I have to admit Gassendi has always suggested the outline of a ruined castle and its turret to me. The rilles in the crater floor (Rimae Gassendi) were readily apparent. As were many albedo features in the foreshortened Schickard crater. These were very well highlighted prompting me to spend considerable time observing them. After about three hours the Moon had reached transit and I called it a night. The Baader 495 nm filter was probably the most effective for contrast detail. Although The Baader Contrast Booster gave the most natural image. The Lumicon #11 made of Japanese Hoya glass excelled at magnifications of 200x and over. This session has effectively concluded my recent triptych of outings with the Big Mak. At the time of writing the Moon is 98.9% illuminated. Which means one of the only features now well contrasted by terminator shadowing is the Grimaldi crater. Although, several years ago, when the lunar phase was virtually identical, I saw possible Transient Lunar Phenomena in Grimaldi. Alternatively the bright flash of light I witnessed may have been a meteor strike. However, that's another story.

 

Lunar images by courtesy of Stellarium & SkySafari 6 Pro

Edited April 15, 2022 by Nightspore

[philjay]

Great reports, wnjoyed reading.

I have lost count on the number of hours I have spent just drinking in the views on the moon. I have an atlas plus virtual moon map and wander around seeing what is around at tge time.

A wratten yellow and or polarising filters are favourites of mine, although I tried an H alpha filter a few times which calms atmospherics peculiarly enough.

 

I had an Orion 127 some years back and loved it, fitted it with 2" diagonal and despite what folks were saying it worked well.

I also had a "real" big mak, the 180 and that gave the best lunar and planetary views I,ve ever had in any of my scopes. It also gave tge worst when conditions werent right, very unforgiving.

 

Not sure what insulating a scope will do, better to let the scope cool fully I would have thought. I spose if you want a quick 15 minute session using the scope as grab and go then it may work.

[Nightspore]

3 hours ago, philjay said:

Great reports, wnjoyed reading.

I have lost count on the number of hours I have spent just drinking in the views on the moon. I have an atlas plus virtual moon map and wander around seeing what is around at tge time.

A wratten yellow and or polarising filters are favourites of mine, although I tried an H alpha filter a few times which calms atmospherics peculiarly enough.

 

I had an Orion 127 some years back and loved it, fitted it with 2" diagonal and despite what folks were saying it worked well.

I also had a "real" big mak, the 180 and that gave the best lunar and planetary views I,ve ever had in any of my scopes. It also gave tge worst when conditions werent right, very unforgiving.

 

Not sure what insulating a scope will do, better to let the scope cool fully I would have thought. I spose if you want a quick 15 minute session using the scope as grab and go then it may work.

 

Thanks Phil. I like polarising filters a lot as well. Anything yellowish also really helps. Light blue filters are good for crater detail, I'm not sure why though. Many 'Moon & Skyglow' filters take out the yellow lines (589nm & 589.56nm) used in most Sodium lamps, which emphasises the blue aspect of the filters. I'm really going to have to try a H-alpha now lol. 

 

 

 

I have a couple of atlases, although I really miss the Virtual Moon Atlas. I don't run Windows anymore and there isn't an easy way to run it on Unix. I may be able to run it on Ubuntu using WINE. 

 

 

I'm confused about insulating Mak's as well, it seems counter-intuitive to me lol.

[+Glafnazur]

I need a good moon atlas, what are the atlases above, they look ideal?

[Nightspore]

2 hours ago, Glafnazur said:

I need a good moon atlas, what are the atlases above, they look ideal?

 

 

The first is the 21st Century Atlas of the Moon I got it from Amazon. The other I've had since I was at school and is the Hamyln 'Concise Guide in Colour Moon Mars and Venus'. It features the famous Rükl map. I believe it is now out of print.

 

 

These are good too. Although Gerald North does tend to 'go on a bit' in his Observing the Moon. Good pictures though. lol

[tuckstar]

+1 for the 21st century, a great book for observing La Luna. That along with my amici prism and its a whole different experience and so easy to navigate and identify features.

[Nightspore]

1 hour ago, tuckstar said:

+1 for the 21st century, a great book for observing La Luna. That along with my amici prism and its a whole different experience and so easy to navigate and identify features.

 

I usually use the Baader 'Zeiss spec' Amici for dedicated lunar viewing. Although I find the bog-standard GSO's are perfectly adequate.

 

[+Streetbob]

Another + for the 21st century. Thanks Andy for recommending. 

[tuckstar]

14 hours ago, Nightspore said:

 

I usually use the Baader 'Zeiss spec' Amici for dedicated lunar viewing. Although I find the bog-standard GSO's are perfectly adequate.

 

Me too. Goes lovely with the telementor and clavè eps 👍