Shadows on the A11 Passive Seismometer Experiment

[MartinC]

I've had a reasonable discussion with a youtube poster and I believe I've addressed his misunderstandings around the different cameras (video/TV) used on the missions.

He's now pointed me in the direction of still images taken during the deployment of the PSE during A11 (AS11-40-5948 - 5950). In particular, image 5950 https://www.hq.nasa.gov/alsj/a11/AS11-40-5950HR.jpg shows the solar panels in light and the panel closest to the camera appears almost translucent whereas 5948 and 5949 show the panels in compete shadow.

Ultimately I'm not overly concerned about addressing the hoaxer but for my own knowledge I would like to try to understand why there is such a difference in the solar panel appearance between photographs. Is it simply down to camera angle and reflected light or am I missing something obvious. I've had a look at the Catalog of Apollo Experiment Operations (NASA 1317) to try and understand the component parts of the PSE but I'm not really any further forward.

Apologies, I'm not sure if I've explained too well but would welcome any thoughts or comments.

[Al Johnston]

I don't think that's translucence showing on the panels, it looks more like reflection of the lunar surface behind them...

[bknight]

I've had a reasonable discussion with a youtube poster and I believe I've addressed his misunderstandings around the different cameras (video/TV) used on the missions.

He's now pointed me in the direction of still images taken during the deployment of the PSE during A11 (AS11-40-5948 - 5950). In particular, image 5950 https://www.hq.nasa.gov/alsj/a11/AS11-40-5950HR.jpg shows the solar panels in light and the panel closest to the camera appears almost translucent whereas 5948 and 5949 show the panels in compete shadow.

Ultimately I'm not overly concerned about addressing the hoaxer but for my own knowledge I would like to try to understand why there is such a difference in the solar panel appearance between photographs. Is it simply down to camera angle and reflected light or am I missing something obvious. I've had a look at the Catalog of Apollo Experiment Operations (NASA 1317) to try and understand the component parts of the PSE but I'm not really any further forward.

Apologies, I'm not sure if I've explained too well but would welcome any thoughts or comments.

49 50 are almost identical while 48 is taken from a much different perspective sowing the backside of the mentioned panel.

If the panel was translucent, which it isn't, then you would be seeing the shadow of the support arms and central copper piece at the bottom of the panel.  Further the large rock at the upper part of the image would show through in the upper panel.  All of these don't show in the panel, so no it isn't translucent.  I agree with Al it is just a reflection.

[MartinC]

I'm now wondering whether it is to do with the angle of incidence.  This map shows the location from which the images were taken https://www.hq.nasa.gov/alsj/a11/A11PlanimetricMapVer1.0LROC-M17512493R.jpg

Images 5949 and 5950 are taken virtually side on to the panels, whereas 5951 is more "front on"

https://www.hq.nasa.gov/alsj/a11/AS11-40-5949HR.jpg
https://www.hq.nasa.gov/alsj/a11/AS11-40-5950HR.jpg
https://www.hq.nasa.gov/alsj/a11/AS11-40-5951HR.jpg

[bknight]

I'm now wondering whether it is to do with the angle of incidence.  This map shows the location from which the images were taken https://www.hq.nasa.gov/alsj/a11/A11PlanimetricMapVer1.0LROC-M17512493R.jpg

Images 5949 and 5950 are taken virtually side on to the panels, whereas 5951 is more "front on"

https://www.hq.nasa.gov/alsj/a11/AS11-40-5949HR.jpg
https://www.hq.nasa.gov/alsj/a11/AS11-40-5950HR.jpg
https://www.hq.nasa.gov/alsj/a11/AS11-40-5951HR.jpg

Excellent observation.

[MartinC]

Sorry bknight I think I posted my additional message at the same time as your post.

I'm sorry I don't think I've explained very well. Images 5949 and 5950 show reflected light on the panels. However, image 5951 there is no reflection. Is this simply as a result of the different camera position (as shown on the map) or do the "properties" of a solar cell have an effect i.e. when viewed from on as opposed to side on?

[onebigmonkey]

Here's that PSE panel from the relevant image stretched so you can see the detail on it as if from head on:



It's also worth looking at AS11-40-5947 & 8

https://www.flickr.com/photos/projectapolloarchive/21445913224/in/album-72157657350941603/

https://www.flickr.com/photos/projectapolloarchive/21881859809/in/album-72157657350941603/

which shows the panels from behind.

And yes, it's all about the viewing angle

[Jason Thompson]

Images 5949 and 5950 show reflected light on the panels. However, image 5951 there is no reflection.

Actually I'm pretty sure there is a reflection. From that angle they are reflecting the sky, which happens to be black. The same can be seen on the upper part of Aldrin's gold visor.

[Bryanpoprobson]

Oh dear this was one of expattaffy’s objections to the moon landings and you certainly can’t have any form of a reasonable debate with him. A thread of over 200 comments IIRC when I pulled him up on it. So I doubt it was expat the op had a “reasonable” discussion with. 😂😂😂

[Bryanpoprobson]

Images 5949 and 5950 show reflected light on the panels. However, image 5951 there is no reflection.

Actually I'm pretty sure there is a reflection. From that angle they are reflecting the sky, which happens to be black. The same can be seen on the upper part of Aldrin's gold visor.

I did a little mock up of this with a correctly angle light source and the reflection is of the shadows on the surface not the sky. It is just a fortuitous angle that there is no lit section of the lunar surface. I did a small video, but it wasn’t a great standard, but I may reproduce it again when I get some time. Where the camera angle changes, a different part of the surface is reflected in between the images.

[Echnaton]

In particular, image 5950 https://www.hq.nasa.gov/alsj/a11/AS11-40-5950HR.jpg shows the solar panels in light and the panel closest to the camera appears almost translucent

At one glance, it looked to me as if the bright spot on the nearest panel is the reflection of the white experiment module in the background.  That hypothesis could be supported or disproved with a bit of math that I can't do, but that module is a good candidate based on the angles and certinly something that your YouTube correspondent would have to disprove before making another case. 

[bknight]

Sorry bknight I think I posted my additional message at the same time as your post.

I'm sorry I don't think I've explained very well. Images 5949 and 5950 show reflected light on the panels. However, image 5951 there is no reflection. Is this simply as a result of the different camera position (as shown on the map) or do the "properties" of a solar cell have an effect i.e. when viewed from on as opposed to side on?

5951 still shows a reflection, but of the shadow this time.

[MartinC]

Thanks for all your input guys, really appreciated.

I've attempted to illustrate the point in question using 2 photographs I've taken of my TV from different angles, one shows a reflection the other does not. https://imgur.com/f63UwUQ
https://imgur.com/piY0PLK I suspect the explanation will be hand waved away, but regardless the exchange with this poster lead me to information about the surface experiments that I'd not seen before which is a bonus.