4.2.3 Apollo 10 Images – Day 3: May 20th

Magazine 34’s next shot of Earth is of Africa, so clearly some time elapses before it is used again. Meanwhile magazine 35 takes over, and the next shot is of AS10-35-5177. That image is shown in figure 4.2.3.1 and analysed in 4.2.3.2.

Figure 4.2.3.1: AS10-35-5177. Source

Figure 4.2.3.3: ESSA 9 (left upper and lower) and NIMBUS 3 (centre left) images compared with AS10-35-5177 and SkySafari time estimate (left). 3D reconstructions using digitally recovered ESSA (above centre) and NIMBUS (above right) data.

SkySafari sets the time at roughly 01:45 for this image, and shows the west coast of north America and Australia just in view. Close examination of the Earth shows that, beneath the thin cloud, the Americas are still there. Australia is more difficult to detect, but the bifurcated thin stream of cloud shown by the cyan arrow is off Australia's east coast at the point where it splits, and what appears to be a small fog bank off Sydney on the satellite photograph is just discernible on the very western edge of the globe.

The Earth, therefore, seems to be where it is supposed to be – a few hours ago the crew were describing north America and now it is only partially visible. Can the satellite timings match up with this suggestion? ATS is not available for this image as it doesn't cover anywhere visible. ESSA's image is still dated the 19th, but is now covering areas that were actually imaged on the 20th, and in this case the orbit that best approximates the line of the terminator is number 1032 (track 5, although in reality the terminator is probably between tracks 4 and 5), which commenced at 23:06.

The NIMBUS image used here is actually a hybrid of two day's passes. The 2 strips of images on the left of the NIMBUS part of figure 4.2.1.24 are actually from the image dated the 20th, and the remainder are from the image dated the 19th.  The track best representing the terminator is number 475, which was commenced at 17:26 on the 19th. The extra amount of rotation brings an additional pass of the NIMBUS infra-red camera into play, and we can see a part of that pass (orbit 479) compared with the cloud band identified by the blue arrow in figure 4.2.3.4.

Figure 4.2.3.4: Section of NIMBUS infra-red orbit 470 compared with the same area of AS10-35-5177

Again, the correspondence between the two is excellent - almost as if Apollo 10 was photographing the weather from space! It’s interesting to note that while the bottom of the NIMBUS image identifies it as orbit 479, the top reports it as orbit 481. Orbit 478 is correctly identified top and bottom, but orbit 482 has a top label of orbit 786! Somewhere along the way the labelling has become confused! Orbit 482’s image (going by the bottom label) shows SE Asia, which is consistent with the numbering, and also shows the same weather patterns as can be found on the ESSA image from that day, so the top one seems to be in error.

After this image of the Pacific is taken there is a gap in photographs of any kind coinciding with a rest period for the crew. At 1d19h50m the crew are having breakfast and being given a summary of news from home, and they describe the view below:

043:49:32 Cernan: Jack, here comes the world. Looking right over Suez Canal, Saudi Arabia, the Mediterranean, Africa, back into the parts of Europe…right now I'm looking at all of Africa, which is almost totally clear with the exception of a few clouds on the western side. I can see across the Straits of Gibraltar, some cloud cover just on the eastern side of the Straits. I can see Spain which is totally clear, Portugal, almost all of the Mediterranean except the north - northwest corner of the Med, Greece, Crete, Turkey, Italy. They all look clear from here. Saudi Arabia, back up into the Soviet Union, is partially clear in great areas and actually almost back into parts of China where the terminator is, it's just sort of partly cloudy. There appears to be a big, long, wide cloud swirl out into the Atlantic west of Spain. Generally, it looks like I can see Zanzibar. Generally, it looks like that whole portion of Africa and eastward – northeastward - is pretty clear today.

The time of this conversation translates to 12:50 GMT on the 20th, and there are two photographs taken on separate magazines that correspond with this time both in terms of where the terminator is, and in terms of what is visible below them.

AS10-34-5042 and AS10-35-5181 both show roughly the same scene of a largely clear Earth dominated by a view of Africa.  The image chosen for comparison with the satellite image is AS10-34-5042, and this is shown in figure 4.2.3.5, along with a close up of Earth in that image compared with the same same close up of AS10-35-5181, and a further close up of the two images focusing on India.

Figure 4.2.3.5: AS10-34-5042 (above left), close up of Earth for AS10-34-5042 and AS10-35-5181, with further close up of India.

The extreme close up of India suggests that AS10-35-5181 was probably taken slightly earlier than AS10-34-5042, as the latter shows the two prominent north-south bands of clouds slightly further away from the terminator. It's also worth noting the shadows cast by those two clouds, which is exactly what you would expect to see from clouds at sunset. In other words they are entirely consistent with where the Sun is in the sky back on Earth.  As usual, however, with different film magazines we can’t discount the role of the medium itself n the slight differences. The analysis of the chosen photograph is shown in figure 4.2.3.6.

Figure 4.2.3.6: ESSA 9 (top left upper and lower), ATS-3 (centre left) and NIMBUS 3 (centre right) images compared with AS10-34-5042. Bottom row: SkySafari time estimate and 3D reconstructions using digitally recovered ESSA (left) and NIMBUS (centre data.

The most obvious point to make about the image is that it shows exactly what the astronaut was describing. The ATS image only just shows the very western edge of what they can see, and certainly doesn't show any of Europe or Arabia. At the time the photograph was taken it would be several hours before those features would be visible on satellite mosaics. We can determine this by looking at the timings of the satellites concerned.

The ATS image shown here is taken just after 17:00 on the 20th. The ESSA image is complicated by the fact that the terminator line falls roughly along the line delineated by the last orbital pass on the image dated the 19th. The ESSA mosaic states that the last pass on that image is number 1037 (track 10), which commenced at 09:03. Track 11 (orbit 1038) passes along the west coast of India and is the first scan on the image dated the 20th, commencing at 11:08. While this is a good 90 minutes before the Apollo image was taken, the final part of the ESSA image covering what is visible in the Apollo photograph would not be imaged for another 5 hours.

The NIMBUS image is more straightforward, and the line of the terminator was covered by pass number 482 at 05:39 on the 20th, but again the final part of the area visible from Apollo wouldn't be completely imaged until around noon when the daylight pass of orbit number 485 finished. It’s worth pointing out in terms of the 3D reconstructions that the data to the east of Africa on the ESSA image is dated almost 24 hours after the pass over Africa itself, whereas the NIMBUS swathes are from the same day, hence the closer match on the NIMBUS image with what we see in the Apollo one.

Speaking of NIMBUS, figure 4.2.3.7 shows the infra-red passes covering the image.

Figure 4.2.3.7: NMBUS-3 infra-red passes 482-485 . Arrows are the same colour as in figure 4.2.3.6

As usual there is an exact match between the NIMBUS and Apollo image, but the real devil is in the details (figure 4.2.3.8).

Figure 4.2.3.8: AS10-34-5042 sections compared with section of NIMBUS-3 orbit 495 (top) and 482 (bottom).

The top section of this image is included mostly for comparison with an earlier image (4.2.2.5), which is obviously different. The Apollo image is again an almost exact match. The lower is is included to show the presence of a tropical cyclone. A number of reports (eg this one) tell of an unnamed cyclone in the Andhra Pradesh region on the 19th, killing over 600 people. Andhra Pradesh is pretty much exactly where this cyclone is pictured and can also be identified in the Apollo image.

About an hour after the image discussed above, Apollo 10 took another set of images of Africa up to AS10-34-5048, low quality source available here: AIA). Little additional information is revealed by these images other than the obvious rotation of the Earth to hide India in darkness as illustrated in figure 4.2.3.9. AS10-34-5043 is matched by AS10-35-5184 and AS10-34-5048 is matched by AS10-35-5186.

Figure 4.2.3.9: AS10-34-5043 (left), 5048 (centre) and SkySafari time estimate for 5048 (right)

The next photographic image to be scrutinised is another case where the same photograph exists on two different magazines. AS10-35-5187 and AS10-34-5049 both show exactly the same scene, and having examined them very closely the only conclusion that can be drawn is that they were both taken at exactly the same time. As for when that time is we have a little help from the mission transcript as well as SkySafari.

SkySafari puts the time at the terminator at around 17:30 GMT, and an hour before that in the transcript the crew describe being able to see the Suez Canal. This is clearly not in shot in the Apollo pictures, so they must have been taken after that time. They are able to describe

047:26:30 Cernan: Charlie, the Suez Canal appears now to be going into darkness. We're looking at most all of Africa, the Mediterranean Sea, Spain, Portugal are in view. So the folks down in that part of the area ought to be getting a good picture of themselves right now.

047:27:12 Cernan: Well, it's a beautiful sight. All of Africa is brown again, of course, and the waters are very, very blue.

047:31:18 Young: …you can see, for, example, the Pyrenees. And you can see there, - maybe cloud cover down along the coast there, down on the Mediterranean coast. You can see, almost see, I think, Gibraltar.

and when asked about the islands around Greece and Italy they say that

047:32:08 Young: They're pretty close to the terminator right now, and it's a little smoggier today than it was yesterday, but yesterday Crete was very clear, l could see Cyprus; the Nile Delta is very clear right now. You can see the Nile; the Nile Valley really stands out, and, of course, the Sahara Desert is very clear, you can see geological features in the desert. It looks like Lake Chad down there in the middle of the – middle of Africa.

Again, the middle of Africa and the Nile are not visible in the image, although Greece and Italy are not quite at the terminator at the time they are speaking.

An hour after the SkySafari estimate they discuss the weather situation over north America, thunderstorms over Brazil. We therefore have some distinctive weather features to look out for in the both the Apollo image, and in the satellite photographs taken on the same day.

Those same distinctive features crop up in the next view of Earth in the time sequence, as shown in a TV broadcast sent down to Madrid. The signal was then sent on to Houston to be rebroadcast later. It’s worth noting that while the mission timeline indicates the recording as being between 16:49 and 17:04, the actual broadcast in the transcript starts just over half an hour earlier.

Figure 4.2.3.10 shows a screenshot from that broadcast compared with the satellite record.

Figure 4.2.3.10: Screenshot of Apollo TV footage compared with ATS (top right), ESSA (middle and bottom right) and NIMBUS (bottom left) satellite images dated 20/05/69. Below that are ESSA (left) and NIMBUS (centre) 3D models built using digitally restored data and right the SkySafari time estimate

As usual the crew provide ample and accurate descriptions of what they are seeing below them.

047:33:12 Young: That certainly is an interesting weather - weather patterns going across there. Now, I can see – I can see right now in Brazil, it stands out very clearly on the horizon. And Brazil is covered with those little thunderstorms that build in a tropical area. It just seems like each tree has its own separate thunderstorm down that way…Boy, it's really a fantastic, just fantastic view. We can see right across the top off the world right now, and it sort of looks like, I don't know exactly how we are oriented, but it sort of looks like the North Pole is open today, but it isn't very much open. The whole northern part of the world is right under the worst cloud bank I've ever seen.

047:34:03 Duke: Roger. That thing has been there constantly almost since, it seems like, since you guys started showing us the pictures back. Do - Can you still see that strange-looking storm system up over the Bering - I guess it was just south of the Bering Straits out over Alaska there. Is that thing still there? It was a funny-looking swirl.

047:34:26 Young: We're right - The terminator runs down through Africa right now, Charlie, so we're starting to look at only about three-quarters of the world.

The next image chosen for analysis is AS10-34-5049, mainly because it is slightly clearer than its equivalent on magazine 35. It is shown in figure 4.2.3.11. By comparison, AS10-35-5187 shows the same view.

Figure 4.2.3.11: AS10-34-5049. AFJ Source

In figure 4.2.3.12, ESSA's orbital data puts the time of the satellite passing over the west coast of Africa at 14:09 on the 20th (Track 1, or pass 1040), compared with NIMBUS orbit 485 over the same zone at 11:20. ATS-3 images were taken at 17:06 & 17:21. As with previous images, while the weather systems visible on the different images are obviously and definitely the same (to the point where the use of arrows to point them out seems both superfluous and ridiculous at times), there are subtle differences between them that indicate atmospheric flux over time.

Figure 4.2.3.12: ESSA 9 (top left upper and lower), ATS-3 (bottom left) and NIMBUS 3 (bottom right) images compared with AS10-34-5049.Below these are ESSA (left) and NIMBUS (centre 3D models built using digitally restored data and SkySafari time estimate.

One example is the system arrowed in yellow. In the NIMBUS image, the earliest of the three, this small group of clouds touches the west African coast and trends north-east inland. There is a clear gap in terms of longitude between those clouds and the mass of cloud over southern Spain. A few hours later in the ESSA image, it has moved slightly further inland and there is no longitudinal gap, and by the time of the Apollo image it has moved further inland still and there is an overlap with the clouds over southern Spain.

To illustrate this point further, a small section of each image from figure 4.2.3.12 has been selected so that they can be compared more clearly – see figure 4.2.3.13.

Figure 4.2.3.13: A section of ESSA 9 (middle),  NIMBUS 3 (left) and AS10-34-5049 on 20/05/69

Allowances need to be made for differences in image projection and quality, but as with other comparisons it is clear that these are the same cloud systems photographed at slightly different times – the Apollo image is not a coloured version of a satellite one.

The next few photographs in magazine 34 show the same scene but taken a short while later. Figure 4.2.3.14 shows the image and SkySafari time estimate.

It should be obvious that there’s only a slight difference between 5049 and 5051, but it’s a difference nonetheless, clearly showing that we are not dealing with a single static view of Earth.

Next in the time sequence is a 16mm image and still from a short opportunistic TV broadcast. It’s shown in figure 4.2.3.15. There’s nothing to be gained from showing the same satellite images and arrows all over again, but it’s worth pointing out that the two sets of images appear to have been taken were taken a short while apart.

Figure 4.2.3.14: AS10-34-5051 above with Earth shown in close up, and a section of the western limb compared with AS10-34-5049 (top right)

Figure 4.2.3.15: 16mm and live TV stills from Apollo 10 compared with a SkySafari time estimate and 3D reconstructions using restored ESSA (left) and NIMBUS data (right).

The distinctive cloud pattern visible in the still image has moved eastwards in the video still, and Africa has now disappeared from view. There is a distinctive curl at the top end of the south American continent where it joins central America, and by the time the video is taken this has also moved eastwards by some distance.

The basis for the timing for the terminator is from the position of the distinctive cloud patterns just above Africa, a small part of which is visible. As will become clear in the next photograph, the clouds around South America put it in the correct place for the timing in this image, and we have these exchanges during the TV broadcast.

049:30:47 Cernan: Charlie, I'm looking at the Earth now through the monocular, and I can see the west coast of Africa. I can see Spain and Gibraltar very, very well. I can see just about 90 percent of South America, up, through Central America. I can see the whole Gulf Coast all the way to California, and on this side now, Cuba is very visibly clear. All of Florida is clear. The whole Gulf Coast is clear. I can look up the East Coast maybe to about the Carolinas, and then it appears to get a little bit cloudy. And it appears that the Great Lakes, I think I can make out Lake Michigan and probably Lake Superior. And then there are some clouds up in the northwestern central United States...Coming out of the North Pole down into the Central Atlantic are some very weird, picturesque cloud formations. Swirls, not definite low areas, but big large swirls.

049:31:44 Cernan:…Coming out of the North Pole down into the Central Atlantic are some very weird, picturesque cloud formations. Swirls, not definite low areas, but big large swirls.

049:32:09 Cernan: It appears to be about the best view that I've been able to have of the whole Atlantic and South and North America from where I am, and it ought to be getting a little bit better as we go along...There are some scattered cloud coverage down in the Caribbean which may make it difficult to pick some of those islands out.

049:54:59 Stafford: Okay. I'll kind of narrate this, Charlie. I'm kind of at an odd angle to hold it out the window. Again, you can see the west coast of Africa, the Sahara Desert, they're all in orange. You can see the Atlantic Ocean with swirls of clouds over to the eastern part of Brazil. You can see the very weird cloud patterns that Gene described out over the northeastern part of the United States. Again, it looks like the North Pole and that whole area around Canada is completely socked in... Again, the one thing that is really so amazing, as you look at the Earth, is the amount of cloud cover that we have down there. Over the tropical rain forest of South America, there's just numerous small cumulus clouds.

049:55:55 Duke: Roger. Can you describe the color as contrasted to say, the Andes or the American Desert?

049:56:03 Stafford: Roger. The color of the tropical rain forest there is more of a greenish brown. It's a greenish brown versus a brown-orange on the tropical - on the American Desert and the Sahara Desert.

049:56:22 Duke: Roger. Can you pick out the Amazon River?

049:56:23 Stafford: Negative. No. I can't pick out the Amazon. I am looking at it with my naked eye where Gene had the 28-power monocular. I do have the zoom on here, so you are seeing it a little bit bigger than we are on the standard vision, so the Earth as you see it there is bigger. And you can see the terminator, or nighttime, has moved over most of Africa at this time, and is starting to move over to Europe. It'll soon be nighttime in Spain, and also, it is getting daylight over in Hawaii, there. The cloud patterns are utterly fantastic as you look out at it.

050:04:49 Young: Roger. In about another hour and a half, you ought to be right underneath us. And, boy, it ought to be the most remarkable picture of the United States ever made. The whole North American continent is just standing out. It's really - and there's not too much clouds, for a change; it's open.

050:05:13 Young: You can see Puerto Rico, Haiti, Jamaica, Cuba, Florida. The Bahamas are under cloud cover right now, but, in general, the whole United States, except for the New England states and a path cutting down through the middle of the United States, Wide open. You can see the GreatLakes very well.

050:05:56 Young: Roger. Mexico and the Yucatan peninsula and even some of Central America. I can't see Panama. I can see parts of Venezuela, Colombia, and, of course, most of Brazil is wide open. Chile seems to be open along the coast down there. Peru and Bolivia are probably under scattered clouds today.

050:08:02 Cernan: Charlie, I've got it out my window now, and, like John said, it's so remarkably clear. Lake Superior and Lake Michigan stand out very brightly. There's just a patch, a little patch of clouds, on the Chicago-Milwaukee area, or else there's snow on the ground. I really think it's probably cloud but you can almost pick out the states by the contour of the sea and the oceans and the lakes. And I can actually see the Mississippi, not see the river, but you can sort of see the Mississippi River Valley as it goes up on north from the delta

050:09:18 Cernan: It's also very interesting just to watch the continents come out over the horizon as the world turns more towards us - as the U.S. Continent turns more towards us.

 050:09:38 Cernan: And I agree now with John. You can see practically that whole island chain all the way down to Trini[dad].

SkySafari has been set to be at the early part of the broadcast and their descriptions match what should be visible at this point. While the 16mm footage does have suggestions of a slightly later time (the distinctive north Atlantic cloud swirl appears to be nearer the terminator), it’s difficult to tell if this is because of the different recording medium. For that reason I’ve not a separate SkySafari estimate.

The next image where any significant degree of rotation has occurred is in AS10-34-5054. This is shown below in figure 4.2.3.16, and analysed in figure 4.2.3.17. An identical view can also be seen in AS10-35-5188.

Figure 4.2.3.16: AS10-34-5054 AFJ Source

No comment is made in the mission transcript (other than the crew saying that they have a fine view of Earth at roughly the right time!), so we are reliant on SkySafari for an exact fix, based on the position of the south American coast on the Apollo image, which gives an estimate of around 20:30 on the 20th, still around 24 hours from LOI.

The time of the ATS image has already been stated as just after 17:00 on the 20th, and the rotation of the globe is such that it is now a close match with what can be seen in the Apollo image, with the exception of the system pointed out by the blue arrow, which is just out of shot. The ESSA & NIMBUS mosaics are still a good match and show all the weather systems visible on the Earth.

As far as their timings go, ESSA's most representative orbit at the terminator is track 2, which in this case is orbit 1041, commences at 16:04 on the 20th. NIMBUS' best orbit is pass number 487, which would have commenced at 14:55 on the 20th.

The infra-red images here also confirm the Apollo photograph’s accuracy (figure 4.2.3.18).

Figure 4.2.3.18: NMBUS-3 infra-red orbits 487-489. Colours used match figure 4.2.3.17

At the risk of being repetitive, once again the Apollo image provides an excellent match with the infra-red observations, and again it’s possible to zoom in closer in these high quality negatives (figure 4.2.3.19).

Figure 4.2.3.19: Section of NIMBUS-3 infra-red orbital pass 489 compared with AS!0-34-5054.

The NIMBUS pass started at 18:11, just 110 minutes before I estimate the Apollo image was taken, which certainly explains the closeness of that match.

Again, we have another photograph demonstrably taken shortly after this one in the form of AS10-34-5055, and again while it isn’t worth doing a full analysis on it it is worth showing it for completeness (figure 4.2.3.20).

Figure 4.2.3.20: AS10-34-5055 compared with SkySafari time estimate

A couple of hours after this photograph was taken we have another TV broadcast and another series of detailed descriptions of the view looking back home. Figure 4.2.3.21 shows the a still from the broadcast, again with 3D satellite reconstructions for comparison.

Figure 4.2.3.21: Still from TV broadcast compared with SkySafari depiction of Earth at the same time and 3D reconstructions using ESSA (left) and NIMBUS data (centre).

The TV broadcast took place between 22:24 and 22:49 on the 20th, and I’ve set Stellarium at 22:30. Here’s what the crew had to say for themselves before the actual broadcast start. At 53 hours and 6 minutes (53:06), or 21:55, they describe the following:

053:06:59 Stafford:…storm center over Alaska. It's finally started to rotate around and has developed into quite a system.

At 53:23 (22:12 GMT), there is a more detailed description:

053:23:06 Cernan: …the eastern seaboard from about the Carolina’s on up, just on the seaboard, is going to be covered with clouds and then into the Atlantic…I mentioned this morning there was a long cloud bank from the northeastern part of the United States into Missouri. It looks like now that that cloud bank goes from central Indiana up across Lake Erie, north-northeastward into Canada…Michigan, Lake Superior, and the Midwest are very clear except for that cloud and there's some clouds which appear to be over - oh, maybe Kansas, Nebraska, I hate to say it, but Oklahoma. I may get some disagreement up here but I think it's Oklahoma, Colorado, Montana, up in that area; and then the West Coast is clear and the Southwest is all clear.

Capcom then confirms that this description matches their weather map, but it isn’t clear weather this is some sort of synoptic chart or a satellite image.

The descriptions continue:

053:23:37 Cernan: Okay, Charlie. And I mentioned this morning there was a long cloud bank from the northeastern part of the United States into Missouri. It looks like now that that cloud bank goes from central Indiana up across Lake Erie, north-northeastward into Canada...Michigan, Lake Superior, and the Midwest are very clear except for that cloud and there's some clouds which appear to be over - oh, maybe Kansas, Nebraska, I hate to say it, but Oklahoma. I may get some disagreement up here but I think it's Oklahoma, Colorado, Montana, up in that area; and then the West Coast is clear and the Southwest is all clear.

053:24:24 Duke: Roger, 10. We're looking at a weather map that was just brought in, and we cast our vote with you, Gene-o. The clouds are over Oklahoma and your description is excellent. It follows a - There's a low pressure up in the very far north turning from the Great Lakes northeastward into - and from - I guess it's up around the - almost to Greenland, it looks like here; and from there, the low pressure weather system with a front comes down into the United States and touches the panhandle of Texas and then goes back on up into Canada again pointing towards Alaska. And there's a band of clouds associated with that on this map, so your description is very accurate.

053:25:13 Cernan: Yes. Yes, I understand. I think you'll see that big swirl of clouds Tom was talking about up Alaska way...Charlie, you asked Tom about the dense vegetation in South America. But if you look at the United States, the Mexican and greater American deserts are that orangish-brown as he described them; but when you look into the Midwest and into the East you go the greenish-brown. It's not the bright orange-brown, it's a darker, more subdued brown - maybe with subtle hints of dark green in it.

053:25:56 Duke: Roger. We copy that. It looks like this cloud system out in the Pacific is associated with another low-pressure system, that's sitting probably north of Hawaii at about 40 degrees latitude. It's located about 150 degrees west, so that's probably what's giving us the cloud pattern up off of Alaska.

053:26:21 Cernan: That's affirmative. That's going to be very easy to see.

While it isn’t easy to see the landmasses to which they refer, the cloud systems are certainly very distinct, and when compared with the next image taken a short while later it does become more obvious that they are accurately describing a real time view of Earth.

When the broadcast actually starts there are more descriptions, mostly tro try and help the ground understand what they’re seeing.

053:40:12 Cernan: Okay, Charlie. you are looking at the world rightsideup, as we know it. The Gulf of Mexico - Mexico goes down and to the right of the picture toward the terminator, South America is in the lower right, and corner of the picture on the terminator. You can look up right smack in the center of the whole picture. You can make out Mexico, is Houston, right on the Gulf, and then North America goes up to about the 11 o'clock position on your picture.

053:40:48 Duke: Roger. We copy. We see primarily just the blues of the ocean and the whites of the clouds. We have a - the cloud patterns are pretty evident. Agree quite - real closely with the weather map I have. It is pretty difficult to pick out the landmasses, though, I must admit. We see one brownish area which appears to be in the American desert, about the center of the globe right now.

053:41:21 Stafford: Yes, Charlie. That's Mexico and the southwestern United States, right there; and Baja California is on the left of that, and the right-          hand edge happens to be the Gulf of Mexico. If you can follow it all up, you will follow it right to Houston and thence New Orleans.

053:41:38 Stafford: It's awfully hard to ascertain the difference - Okay, Charlie. It's hard to ascertain between the water down there in the Gulf and the landmass, because the whole eastern coast of the United States looks a greenish brown versus water.

053:41:58 Duke: Roger. That helps us out here to locate ourselves, at least for me, 10; and I think I see where you are talking about now. We have one section of clouds that looks like it is almost a circular area - a clear area and then clouds appear to come out of South and Central America - swing out into the Pacific and in the center of that it looks like the clear area which I am saying is the southern part of the United States, from Mexico along the Gulf Coast. Is that correct?

053:42:35 Cernan: That's it, Charlie. The Gulf of Mexico is right smack in the center up and down of the world. If you follow the terminator down and              went halfway and then went about halfway from there toward the rounder part of the Earth, you will find the Gulf of Mexico on that brown area you are           looking at, between Mexico and the southeastern United States. That's Houston right smack in the center of that clear area...goes from Central America          right on up into the states.

053:44:03 Stafford: Okay, Charlie. The total globe that you see there is bigger than what we actually see, since we have the zoom lens on and it is probably  about one and one-quarter times as big as we see it.

053:44:17 Duke: Copy, 10. As I said earlier, we are primarily getting the globe on a black background, and we see the white of the clouds and the blues  of the sea with an occasional glimpse of what I make out as landmasses in the brownish. But, it is really difficult for an untrained eye to pick out the exact landmasses. We are sitting here with the in-pad book that - We got it to show the various sizes and with this diagram, it is a big help.

053:45:12 Duke: I think what it is, 10, is the landmasses and the clouds tend to wash out and it is a little hard to discern the difference; but looks like we can pick out the shapes of Yucatan, Florida, and Cuba, and the Gulf of Mexico.

053:45:40 Cernan: …If you follow up…the Gulf of Mexico there - and then go straight north you see a little bit of V in the clouds and there's one going off to the right and a little thin sliver going to the right is the one I've been mentioning all day that goes from Indiana on through the northeast part of the country; and then that bigger blob that forms the left-hand side of the V is over the north, central United States and then right smack in center of the V is Lake Superior and Lake Michigan.

053:46:20 Cernan: And then way up on the upper left-hand, maybe about 10 o'clock on the globe, you will see a funny cloud pattern that sort of looks like a sea serpent of some sort with his beak pointing to the right. That that cloud pattern that Tom was referring to up in the Alaska area.

From this description that the cloud mass he is describing is the large mass over the northern US identified by the purple arrow in the next image, AS10-35-5068 which is shown below in figure 4.2.3.22. The comparison with the satellite images is done in figure 4.2.3.23.

Figure 4.2.3.22: AS10-34-5068. AFJ Source

Figure 4.2.3.23: ESSA 9 (top left upper & lower), ATS-3 (bottom left) and NIMBUS-3 IDCS (bottom right) compared with AS10-34-5068. Below these are ESSA (left) and NIMBUS (centre) 3D models built using digitally restored data and a SkySafari time estimate.

The disappearance of most of south America beyond the terminator puts the time at 23:15, with the satellite images showing weather systems from the 20th. As far as the satellite timings are concerned, ATS is obviously from the same time as before, and nearly all of the land masses visible are now beyond its view. We can also see that the large swirl described in the TV commentary is identified by the blue arrow here. Not for the first time we have a very clear Hasselblad image showing exactly what was filmed and described in the TV footage.

As for satellite timings, ESSA's terminator position would have been on track 3 of its circuit, or orbit 1042, commencing at 18:09 on the 20th, but the area over the Pacific wouldn't be imaged for another hour after the photograph (track 6, orbit 1045). NIMBUS' track 489 was commenced at 14:55 on the 20th, and not all of the area in the photograph was imaged on the 20th.

The next photograph in the series showing rotation of the Earth is taken on day 4, so click on the links to get there.