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Apollo 11 Landing Site

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#1 Tom Glenn

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Posted 21 March 2018 - 04:32 AM

I’ve been waiting out the weather by editing images that I captured on some of the better nights in the past year.  I wanted to find my best example of the Apollo 11 landing site, and I happened to have a decent one from the morning of September 10, 2017.  As an added bonus, the Apollo 16 landing site is also visible in the overview of the region, but unfortunately I did not have a higher resolution image of this region so I am focusing on Apollo 11 here. 

 

The following image was taken with a C9.25 Edge HD and ASI224mc camera at F/10, 25% of 5000 frames stacked, and 6 panels used to create a mosaic.  The boxed region depicts approximately the region shown in the next image that was captured with the same scope and camera but at F/22.  The last image is a cropped and resized version of the landing site region, with a few notable landmarks labelled.  The contrast has been enhanced and due to the resizing it may no longer look as aesthetically pleasing but I think it makes it easier to see the landmarks.  Click to see full size. 

 

40225131834_46d22ccb62_c.jpgApollo11_panorama by Tom Glenn, on Flickr

 

 


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#2 Tom Glenn

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Posted 21 March 2018 - 04:33 AM

Apollo11_CN.jpg


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#3 Tom Glenn

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Posted 21 March 2018 - 04:34 AM

Apollo11_zoom.jpg


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#4 Tom Glenn

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Posted 21 March 2018 - 04:35 AM

For a fun comparison, here is a NASA photograph of the same region taken from the Apollo 11 lunar module (labels in photograph are by NASA).  Note that it is rotated 90 degrees clockwise from my image, and the shadows in the craters clearly show it occurs during lunar morning, whereas my image was taken during lunar evening.

 

https://www.hq.nasa..../A11LBL5447.jpg

 

And here is a higher resolution version of the same photo from NASA, unlabeled.

 

https://www.hq.nasa....1-37-5447HR.jpg

 

This photograph is fascinating because it was taken from the lunar module exactly one orbital revolution before touchdown on the surface, from an altitude of approximately 62 miles.  The command module Columbia is seen in the photo, at a slightly lower altitude than the lunar module because after undocking of the two spacecraft, a visual inspection of the lunar module was required and they wanted the blackness of space as the background for this inspection.  Shortly after this photo was taken, a separation burn was initiated to alter the orbital trajectory of the lunar module and begin the descent to the lunar surface.

 

The Cat’s Paw is really the only feature that was visible to the astronauts on the surface of the moon that we can see from ordinary telescopes on Earth.  Here is a NASA annotated photograph taken from near the lunar module on the surface showing the raised rim of Cat’s Paw on the horizon.  The photos on top were taken by Buzz Aldrin, and on the bottom is Cat’s Paw from overhead and “West” crater which is very near the landing site.

 

https://www.hq.nasa....det5882-82a.jpg

 

For those interested, you can access the entire library of Apollo 11 images from NASA here:

 

https://www.hq.nasa....1/images11.html


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#5 MalVeauX

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Posted 21 March 2018 - 05:11 AM

Really nice mosaic!

 

Very best,



#6 TareqPhoto

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Posted 21 March 2018 - 06:07 AM

Very nice, i really like the quality of your image too, pity i went with a Mak instead of a SCT, so hope once i figure out things i can have nice quality with my Mak.

 

Hope i can find or get that area of the moon where Apollo landed, good to have some memorials.

 

Did you use any filter for those images?



#7 deepwoods1

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Posted 21 March 2018 - 06:51 AM

Interesting to see from different points of view. Thanks!



#8 Luc CATHALA

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Posted 21 March 2018 - 07:33 AM

Hello

Nice images and interesting informations. Thank you.

Clear skies.

Luc



#9 Tom Glenn

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Posted 21 March 2018 - 02:51 PM

Thanks to all for the nice comments.  To answer the question about filters, for these images I used a standard IR cut filter with a bandpass of 400-700nm.  


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#10 BeltofOrion

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Posted 21 March 2018 - 06:24 PM

These look great, Tom. Very interesting how perfectly circular the rim of some of some of those craters appears to be.



#11 Tom Glenn

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Posted 21 March 2018 - 06:36 PM

These look great, Tom. Very interesting how perfectly circular the rim of some of some of those craters appears to be.

 

Thanks, indeed the shadow profile inside craters is indicative of the shape of the rim, and while some lunar craters yield interesting patterns, many in these views give very smooth profiles.  The high resolution NASA photos show very distinct circular shadows as well.  Because the moon has no atmosphere, there is nothing to distort the shape of a shadow other than the terrain itself, and furthermore the shadows are very sharp because there is no atmospheric scattering. 

 

Speaking of shadows, here is another NASA photograph, shot by Buzz Aldrin on the surface, in which you can see his shadow, and part of the rim of Cat's Paw in the distance.  

 

https://www.hq.nasa....1-40-5882HR.jpg


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#12 BeltofOrion

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Posted 21 March 2018 - 10:59 PM

Now that's interesting. The shadows of the rocks on his left point to the right, while those on his right point left. A couple of Kleig lights set up behind him? Then there would be two sets of shadows on each rock, I suppose.


Edited by BeltofOrion, 21 March 2018 - 11:04 PM.

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#13 Tom Glenn

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Posted 22 March 2018 - 01:05 AM

Good observation on the shadows.  Most of this is due to perspective.  The lens is in the center of the photograph, and the sunlight is coming from directly behind.  The shadows appear to converge towards the centerline in the same way that if you drive down a straight road, or look down a hallway, the parallel lines on either side appear to converge in the distance even though they do not.  In fact, many of the Apollo photographs have even more shadow variation than this one, and this is always a favorite topic of conspiracy theorists, who claim that every shadow should be parallel, which is false.  Mythbusters even covered this once in an episode.  In addition to perspective, which is the biggest factor at play here, there are also extreme variations in shadows that can result from varying terrain.  There is a Wikipedia article that gives a few examples of photographs.  Look at the extreme shadow variation in this one:

 

https://en.wikipedia...1-40-5961HR.jpg

 

You can easily set up your own experiments with a spotlight behind you at night to test all of this.  The most significant of the effects at play is perspective, but geometry and profile of the objects is also important.  If you illuminate from behind and place a few objects some distance in front of you to the left and right, you can create all kinds of interesting shadow profiles that do not appear parallel from your perspective, either through a camera lens or your own eyes.  And if you then keep the light source in the same location but move yourself to a different vantage point, the perspective will change. 

 

 

 



#14 flt158

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Posted 22 March 2018 - 02:22 PM

Hello, Tom. 

All your images are truly astounding!!

Allow me to share with you what I observed on the Moon on the evening of 21st February 2018. 

I have a William Optics 158 mm F/7 apochromatic refractor, and I used magnifications 112X, 140X, 167X, 225X and 280X as I observed the Moon on that occasion. 

The Moon was 6 days old and I could see the 3 central peaks of Cyrillus and Theophilus perfectly. 

The terminator was a little west of Mare Tranquillitatis. So it was easy to see Ritter, Sabine, Schmidt, Manners, Arago, Lamont (for the first time), Moltke, the 2 domes Arago Alpha and Arago Beta, Maskelyne, Ariadaeus and Julius Caesar. 

As I increased the magnifications to 225X and 280X, I observed Rimae Ritter and Rima Ariadaeus. There were wonderful to behold. Then I discovered I could see the Apollo 11 craters Aldrin, Collins and Armstrong. It is only my second time to observe them. 

Unfortunately I did not see Sabine C. Maybe next time. 

 

Clear skies from Aubrey. 


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#15 Tom Glenn

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Posted 22 March 2018 - 10:31 PM

Thanks for the comments Aubrey, and thanks also for sharing your description of the region.  Sounds like you had a good night of viewing!  The lunar phase you observed was nearly identical to the phase during the Apollo 11 landing, so the features were well illuminated for viewing.  Any time you can see craters under 3km visually I consider it a pretty good night, so you were doing well to get Collins at 2.4 km.  Cat's Paw is always challenging to see visually, because it is fairly shallow and low contrast.  You also were observing one day later from when I took this image on Feb 20 with a 4.5 inch reflector:

 

https://flic.kr/p/251iZky



#16 flt158

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Posted 23 March 2018 - 10:57 AM

Hello, Tom once again. 

I did not know what phase the Moon was showing as Apollo 11 landed in July 1969. 

I was only 9 years old at the time. But I do remember my mother being very excited about it. 

The night after February 21st, I was able to show my wife the Lunar X and V. 

It thrills me when Dave Mitsky give us the times for those events on Cloudy Nights. 

 

I thank you for your encouraging reply, Tom. 

By the way your surname is rather famous in astronautical circles!!

Perhaps you are related to someone famous. 

 

Aubrey. 



#17 schu

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Posted 24 March 2018 - 09:29 PM

This is really good stuff, Tom. Incredible images

 

I was doing some research a couple of months ago - I was 20 years from being born when the moon landings happened!  But they specifically launched during the 1st quarter moon phase so that their landings would be near the terminator as viewed from earth - so they covered all the bases.  Telemetry - the site faced Earth, temperature (full lunar daytime is really hot, and night very cold) as well as visibility - the shadows created near the terminator provided some good visual features for landing navigation.  They varied their launch dates to match up with the lunar phases that would place the terminator near the intended launch sites for all of the Apollo missions.


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#18 Tom Glenn

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Posted 26 March 2018 - 03:18 PM

By the way your surname is rather famous in astronautical circles!!

Perhaps you are related to someone famous. 

 

In this case, it's just a coincidence.  But thanks for the comments!


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#19 crossingsymmetry

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Posted 01 April 2021 - 07:36 PM

Quite an amazing picture. I was able to find the sites using Celestron 8SE without much trouble! Thank you for the tips and posting your images. 



#20 jgraham

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Posted 01 April 2021 - 07:50 PM

Coolness! I have been following the flight on Apollo 11 in real time, I just listened to the splashdown. I love how your image shows the Cat’s Paw and Highway 1. Nicely done!



#21 Tom Glenn

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Posted 02 April 2021 - 04:20 AM

Thanks for the comments......I'm glad to see this old thread (now three years old exactly) is still generating some interest and proving useful.



#22 Borodog

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Posted 02 April 2021 - 11:16 AM

Very nice work, Tom.



#23 Stefano Delmonte

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Posted 05 April 2021 - 04:09 AM

Either the original photo then the edited landing site show amazing details!

 

Curiously ,in the Nasa image you post, the CSM module show the same size then Collins crater, 3.9mt vs 2.4km, maybe with some trigonometry is possible to calculate the roughly CSM altitude...

 

Ste



#24 Tom Glenn

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Posted 06 April 2021 - 02:10 AM

Curiously ,in the Nasa image you post, the CSM module show the same size then Collins crater, 3.9mt vs 2.4km, maybe with some trigonometry is possible to calculate the roughly CSM altitude...

 

Absolutely.  Not only is it possible, but it is quite accurate.  All we need to accomplish this is data about the image scale, which can be obtained with knowledge of the focal length and the scan size of the raw film.  This data can be obtained from the original source. 

 

http://tothemoon.ser...mm#AS11-37-5447

 

From this, we see the image was captured with an f/2.8 Zeiss lens, focal length 80mm.  Also, we know from reading the documentation of the film scanning process that the scanner used has 5um pixels.

 

http://apollo.sese.a...CANS/index.html

 

This allows us to calculate the image scale at 12.88"/px.  If you download the full sized image, you can then easily measure features.  Shown below is a highly reduced representation of the complete film scan, but I downloaded the full sized image, which is over 14,000 pixels across. 

 

AS11-37-5447.jpg

 

I measured Collins crater at approximately 410 pixels in the full sized image, which equates to an angular diameter of 5281", or 1.47 degrees.  This same region of the image corresponded to 2.8km across the lunar surface when measured with LROC data.  Now, using the simple trigonometric relationship of tan(1.47)=2.8km/X, we can solve for X=109km, which represents the approximate altitude of the spacecraft above the lunar surface.  Checking the Apollo flight journal, the reported altitude at time of the decent burn was approximately 60 nautical miles, which is equivalent to 111km, for an error of less than 2% from my estimate.  

 

Further, we can use the diameter of the command module Columbia of 3.9m to determine the approximate separation distance between the CSM and LM.  The measured width of the Columbia CSM in the full sized image is 392 pixels, which yields an angular diameter of 5049", or 1.40 degrees (as you point out, very similar in apparent size to Collins crater).  Using the relationship tan(1.40)=3.9m/X, we solve for X=159m, which represents the separation distance between the LM and CSM at the time of the image.  


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#25 Stefano Delmonte

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Posted 06 April 2021 - 11:47 AM

Thanks Tom for the accurate explanation/exposition, last time I used trigonometry was 30 years ago so I'll keep this for future mesurmentswaytogo.gif

 

Ste




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