4.5 Apollo 13

While the global populace had tired of the Apollo missions, questioning the value of missions in the face of social problems at home and abroad (Gil Scott Heron's “Whitey's on the Moon” captured the mood of many), NASA still had several missions to run, even if the numbers of them were being decreased by budget cuts.

Apollo 13 was launched on April 11th 1970 at 13:13 GMT, intending to land at Fra Mauro on the 13th.  As anyone with even a remote grasp of modern history knows this didn't happen. A routine stirring of storage tanks led to a spark that caused an explosion in an oxygen tank, crippling the CSM and causing a substantial proportion of the crew's oxygen supply to evaporate into space. Already well on their way to the Moon, the crew had no option but to carry on towards it and use a gravitational slingshot technique (theoretically understood but never before tried) to propel the craft home after a far side lunar pass.

During the mission, they did manage some Earth photography, especially in the early stage of the mission when a weather photography programme meant an image of Earth was taken every 20 minutes. Later on in the mission, there is a poignancy to the many photographs of home that the crew took and that will be used in this analysis.

Altogether 5 magazines of film were used, exposing 604 images. Many of these are focused on the stricken craft, and of the Moon during their slingshot pass.

The crew did make several TV broadcasts, but such was the decline in interest that the 3rd one, immediately after which came the accident, was recorded instead of transmitted live, and it was shortly after this broadcast that the fateful instruction to stir the tanks was issued. The mission timeline cataloguing the events can be found here: NASA source.

Publicly available satellite imagery is in limited supply compared with previous missions. The NIMBUS-3 satellite had reached the end of its useful life as far as visual imagery was concerned and is not available here. The replacement NIMBUS-4 had not yet started full visual recording of its orbital passes (these commenced in full from April 18th). A test image of Scandinavia for the 13th of April can be found in the NIMBUS data catalogue volume 1, but examination of the photographs available from the Apollo mission revealed that no Earth images were taken that day. An image dated April 10th from NIMBUS 4 (see here) was made available for sale on eBay. The image was not released to the press until the 29th (if the text on the reverse is to be believed). This image is included in figure 4.5.1 for comparison. Other modern remappings as geotiffs of the NIMBUS IR data are available here and are included where appropriate.

Given that the crew were somewhat pre-occupied with an exploding spacecraft at the time, this is hardly surprising. This article ESSA News, and this ESSA World article briefly describe the role of satellite meteorology in the rescue effort, but supply no images.

There is also an image available from what appears to be ATS-1 for April 16th showing the Apollo 13 landing site (used to predict likely weather conditions on Apollo 13's return) found in the ESSA publication The first five years of environmental satellites, but while several Apollo photographs were taken on the 16th none of them fell over the area covered by ATS-1.

We are therefore left with the ever reliable ESSA-9 and ATS-3. ATS-3 is not available for all the days of the mission, but is used where possible. ESSA's catalogue can be found here. ATS data are contained in the same volume as those used in the preceding section for Apollo 12. An interesting alternative to the ESSA images comes in this video, which has the images in a ‘flat’ projection and in colour! The Apollo images used are from the Apollo Image Atlas, with the exception of a screenshot from the first TV broadcast. There are a few high quality TIFF images available at http://archive.org/ (namely AS13-60-8588, AS13-60-8591 and AS13-60-8600).  All of the http://archive.org images are incorrectly described as being on the journey home. As will be seen shortly, they were all taken on the way to the Moon.

3D reconstructions will be used for date when the digitally restored versions of satellite data are available

4.5.1 Satellite comparisons

Before looking at the post-TLI images it’s worth looking at an Earth orbit image and a brief image of Earth from a broadcast made in Earth orbit as systems were being checked out. The orbit photograph shows us a view of Baja California, and as the transcript has this:

001:31:13 Swigert: And we're just coming up on Baja, and I've got the TV on. Do you want it?

It seems likely that this is when the photograph was taken. The time translates to 19:25 on the 11th. The image in question is shown below in figure 4.5.0a, together with satellite views.

Figure 4.5.1: Screenshot of Apollo 13 16mm footage compared with ESSA-9 (left) and ATS-3 (right). Below this is an image recently sold on eBay taken by NIMBUS 4 on the 10th - the cloud over Florida is much further north on this.The screenshot has been rotated to give the correct perspective.

It is not immediately apparent from the screenshot shown in the figure above, the darkness in the top right corner of the Earth image is actually the terminator line, something that can be seen more clearly when looking at the footage in its entirety. The time of the quote given in the transcript is 23:01 GMT, and if this is translated into Stellarium from a lunar viewpoint, the terminator line is as shown in figure 4.5.2.

Stellarium suggests a terminator line just off the east coast of northern America. The terminator line in the Apollo screenshot is just to the east of the cloud system identified by the green arrow, and the outline of north America on the ESSA satellite image corresponds exactly with this. The Gulf of Mexico is visible in the bottom right corner of the image, below the green arrowed clouds, and the yellow arrowed cloud is over the Texas/Mexico border.

The ATS image is recorded as taken at 16:23, just over six and a half hours before the Apollo image. ESSA's orbit for that part of north America is track 3, or orbit 5114, which commenced at 18:08. The terminator orbit (5113) was commenced at 16:02.

The satellite images confirm that the footage shot by Apollo 13 as it left Earth for the Moon does indeed show the clouds it should have seen.

Figure 4.5.2: Stellarium representation of the terminator line at 23:02 GMT on 11/04/70

Once safely on the way we begin to see images of the Earth as an entire disk. The first photograph showing the Earth as such is AS13-60-8588 (see figure 4.5.3).

Figure 4.5.3: AS13-60-8588. Source given in text.

This Apollo image is compared with the ATS and ESSA images from April 11th below in figure 4.5.4.

The additional rotation of the Earth between the earlier screenshot and the Apollo image suggests a terminator line consistent with a time of around 23:45 on the 11th. Zooming in close to the Canadian border on the east coast shows that the great lakes are just visible, and Florida would probably be visible if it wasn't covered in cloud.

Of the two satellites ESSA has the best coverage here & the timings are the same as the previous image. The streams of cloud off Baja California are just visible in the ATS image, as is the large system peeling off the Antarctic (cyan arrow), but the north Pacific weather patterns over Hawaii (red arrow) are too far around. A few hours later in the mission comes a period occupied by weather photography. The idea was to photograph the globe at roughly 20 minute intervals. The exact reasons for it are not clear, but the assumption must be that as the exact time of the photograph is known, this can be tied in more precisely to ground based meteorological recordings.

The first image was taken at exactly 02:30:45. The next image of Earth is AS13-60-8590, and this is followed by 10 further ones. In the mission transcript at 11:24 hours in to the mission (06:37 on the 12th), the crew report that they believe they have taken 10 images and will take one more. As AS13-8590 is succeeded by 10 more images, then logically it must be the first in the series, and we can therefore attach a precise time to it.

Figure 4.5.5 shows this image, and figure 4.5.6 the satellite image comparison.

Figure 4.5.5: AS13-60-8590, source AIA

The weather system identified by the red arrow is clearly the same as that in figure 4.5.4, and the clouds picked out by the blue arrow, although not identified specifically in the preceding analysis, is very obviously the same one.

Land masses are not readily obvious in either Stellarium or the Apollo image (which in itself is an indicator that the time for both is correct), but for those that wish to zoom in close enough, land is visible through the cloud cover towards the top of the globe, at what would correspond with north-east Asia around Kamchatka and Siberia. The blue arrowed system starts out over Alaska.

We already know the time of the ATS image, and the Earth as far as Apollo is concerned has evidently moved on since it was taken. ESSA's orbit covering the north Pacific best here is track number 6, or pass 5117, commenced at 00:03 on the 12th, so the Apollo image was taken within a few hours of the satellite version.

Given that the next photograph in the sequence (AS13-60-8591) was taken at 02:52, 22 minutes after the preceding one, we have another excellent opportunity to demonstrate that the Earth used in the Apollo images was the real one, rotating at the correct speed, and not a stationary image superimposed on a background. Figure 4.5.7 shows the terminator line near the weather system picked out by the red arrow above in AS13-60-8590 & 8591.

Figure 4.5.6: AS13-60-8590 compared with ESSA (top & bottom left) and ATS (right) satellite images. Stellarium estimate of time at terminator. Cyan, magenta and red arrows are the same as on figure 4.5.4.

It is quite obvious from these two images that the Earth has moved, and moved roughly the sort of distance you would expect it to have moved in around 20 minutes – roughly 5 degrees of longitude, or around 400 km at the latitude of these clouds.

The final image in the sequence of Earth images used here is AS13-60-8600 (figure 4.5.8). This is the 11th in the series of weather observation photographs, and is pinpointed in the mission transcript as being taken at 06:50:17 on the 12th. As by this time the viewpoint of ATS-3 has long since been passed, only ESSA's images can be used to compare the clouds, and this is carried out in figure 4.5.9.

Figure 4.5.8: AS13-60-8600. Source AIA

Figure 4.5.9: AS13-60-8600 compared with ESSA satellite image and Stellarium estimate of terminator. Left is a 3D reconstruction using digitally restored ESSA satellite data.

Stellarium suggests that by the time of the Apollo image Australia should be fully in view, and indeed it is.

The cloud mass identified by the green arrow is the one to the west of the system picked out in blue in figure 4.5.6, and the red arrowed band of cloud is a continuation of the one picked out in green in figure 4.5.6. As for whether ESSA's timings can confirm the time given by the Apollo mission and Stellarium, the most relevant track is number 8, which corresponds to pass 5119, commenced at 04:04 on the 12th. Again, ESSA's pass over Australia falls within a couple of hours of the Apollo image.

If the sequence of photographs taken by Apollo 13 as the earth recedes behind it are strung together as a video, the result can be seen below:

Figure 4.5.10: AS13-62-8886, source AIA

The key to identifying this image as belonging to the 14th of April is the cloud system off western Europe (cyan, green and blue arrows) that extends into the Atlantic to off the west coast of Africa. These clouds patterns do not appear in this formation on other days, and as will become clear, the system pointed out by the blue arrow moves progressively towards Africa over the next couple of days. What will also become clear over the next few images is that the blue arrowed clouds are connected to a weather system that extends over America that is visible in subsequent images.

Returning to this analysis, Stellarium's terminator line through Libya puts the time at around 16:30 on the 14th, just over 13 hours after the crew reported that they had “had a problem”.  The ATS image is recorded at 14:01. ESSA's most relevant pass is pass 5148 (track 12), which was started at 12:08. As usual, the reason for the close correspondence between the satellite images and Apollo is that there is relatively little time between them.

The next image in the sequence for the 14th is AS13-60-8601 (figure 4.5.12). Readers may wish to compare it with AS13-62-8901, which shows an almost identical viewpoint but is of inferior quality. Figure 4.5.13a shows this image compared with the available ESSA, ATS and NIMBUS geotiff images, while 4.5.13b shows a close up of the area east of Greenland compared with a higher resolution image taken by NIMBUS’s IR cameras.

Figure 4.5.12: AS13-60-8601. Source: AIA

Figure 4.5.13a: AS13-60-8601 compared with ESSA (top left), ATS (bottom left) and NIMBUS IR satellite images (bottom right). Stellarium estimate of time at terminator to left. Right are 3D reconstructions using digitally restored ESSA (right) and NIMBUS IR (far right) data.

Figure 4.5.13b: Crop of AS13-60-8601 (right) compared with close-up of NIMBUS 4 IR image.

In the overall image, once 'correctly' oriented, the Florida coastline becomes very obvious, and makes positioning a Stellarium terminator much simpler, placing the time at around 20:45 on the 14th. The close up of the IR image beautifully picks out the swirl of cloud off Greenland.

At this time in the mission the crew are involved with almost continual dialogue with Capcom about the state of the vessel, levels of consumables, and upcoming manoeuvres to orient the craft and position it on a homeward trajectory ahead of a far side lunar pass.

The weather systems picked out by the cyan and green arrows are continuations of weather systems identified in figure 4.5.11 by the blue arrow. The ESSA orbit for the mid-Atlantic would be pass 5150 (track 1) which was commenced at 15:08.

The next image in this sequence is AS13-60-8716 (figure 4.5.14, source AIA). The photograph occurs after a large number of far side images, and therefore must have been taken after 00:46 on the 15th when they emerged from behind the far side. AS13-61-8826 features a very similar image of Earth (when zoomed in), and this also has far side images preceding it. The ever decreasing lunar disc shown on both these magazines suggests that the image would have been taken well after the TEI burn that occurred at 02:45.

Figure 4.5.14: AS13-60-8716. Source given in text

As can be seen in the analysis in figure 4.5.15a, the dominant weather system visible is in the Pacific, so don’t have an ATS image, but we do have ESSA and NIMBUS data available. A close up the NIMBUS image is shown in 4.5.15b.

Figure 4.5.15a: AS13-60-8716 compared with ESSA and (top left), 3D reconstructions of digitally restored ESSA (centre left) and NIMBUS IR (centre right) NIMBUS IR satellite images (left) and Stellarium estimate of time at terminator (above).

Figure 4.5.15b: NIMBUS IR image compared with a crop of AS13-60-8716

The dominant weather system (blue arrow and shown in 4.5.15b) on the map is a development of the one identified by the blue arrow in figure 4.5.6, and its centre is still located roughly over Alaska & Kamchatka. Close inspection of the south-west horizon shows that Australia is just visible, and this helps to pinpoint the time as being roughly 05:00 on the 15th.  As far as ESSA's timings concerned, the image used is dated the 14th, but the most relevant orbital pass for this part of the globe is orbit 5155 (track 6), which was commenced at 01:04 on the 15th, again just a few hours before the Apollo image was taken.

The next image in the sequence is AS13-61-8864 (source: AIA). This photograph occurs at the end of a sequence of images showing an ever decreasing Moon. Towards the end of the magazine, there are a couple of photographs of the adapted lithium hydroxide canisters used to scrub the cabin air clean of surplus carbon dioxide. The procedure to adapt these canisters began at around 90 hours in, or around 13:30 on the 15th, so the images of the Earth must have been taken before then.

Figure 4.5.16 shows the original Apollo image, and figure 4.5.17 the same image compared with satellite photographs.

Figure 4.5.16: AS13-61-8864 – source given in text

Figure 4.5.17: AS13-61-8864 compared with ESSA (top left), 3D reconstructions of digitally restored satellite ESSA (centre left) and NIMBUS (centre right), NIMBUS satellite IR data (left) and Stellarium estimate of time at terminator (above). Cyan, green and red arrows as figure 4.5.15.

What the image shows is that weather patterns that were towards the west of the globe have moved much closer towards the terminator, and systems identified in figure 4.5.15 can also be identified in figure 4.5.17. Australia's position on the terminator allows a relatively precise estimate of the time the image was taken: 08:15. As the satellite photograph is dated the 14th this gives the appropriate orbital pass as number 5158 (track 9), commenced at 07:01 on the 15th. A few hours after the Australias enter darkness, ESSA starts a new collection of orbits that will have the next day's date on them.

Two images later in this magazine we have a similar view in AS13-61-8867, again with the Earth framed by the LM quad thrusters. As with other Apollo images that are ostensibly identical, close examination reveals that there are differences along the terminator that show that it was taken a short while after AS13-61-8864, rather than at the same time.

AS13-61-8867 is shown in figure 4.5.18 below together with a zoomed and cropped Earth.

The storm over south western Australia as moved to almost in darkness, and the setting the time any later would move it too far, and it does act a further confirmation that the two images are not the same photograph.

There are no firm hints in the transcript specifically about these last two photographs, but capcom is informed regularly at around this time of the angle at which Earth appears on the LPD (Landing Point Designator - marks on the LM window designed to aid distance gauging), and at 85:04 (around 08:20) Haise tells Earth that they are:

“just looking through the command module at you now“

so Earth is on their minds!

The next Apollo image to be looked at is AS13-60-8720 (Source: AIA). There are no real clues in the remainder of this magazine as to when it might have been taken, other than it is after images previously examined from this film, so we are reliant in what we can see in it (figure 4.5.21). Figures 4.5.22a & b show the satellite images as a comparison.

Figure 4.5.21: AS13-60-8720. Source given in text.

Figure 4.5.22a: AS13-60-8720 compared with ESSA (top left), NIMBUS (centre right) and ATS (centreleft) satellite images, with Stellarium estimate of time at terminator above. Right are 3D reonstructions of digitally restored ESSA (right) and NIMBUS IR (far right) satellite data.

Figure 4.5.22b: AS13-60-8720 zoomed and cropped and compared with NIMBUS IR image.

It doesn't take much zooming in on this image to see that the terminator line crosses north Africa somewhere along the coast of Tunisia/Algeria, which gives a time of the photograph as around 18:00.The main weather system visible over the Atlantic is the same one observed in figure 4.5.11, but it has changed in the couple of days since it was first photographed, separating itself from the other clouds in the mid-Atlantic and rotating so that the south-western tip is closer to Africa than it was previously. The close-up NIMBUS image nicely shows the swirl of cloud in the Atlantic

The movement of the Earth has also brought the ATS satellite back into play when confirming the timing of the Apollo image. ATS' image is time stamped at 15:59 on the 15th. ESSA's most representative orbit is pass 5161 (track 12), which commenced at 13:06 – not long before the ATS image, and within a few hours of the Apollo photograph.

The next picture to be analysed is the final image in magazine 60: AS13-60-8726. Between the preceding image and this one there are only a few pictures of a now very small Moon. Magazine 62 again has a very similar image in AS13-62-8954, but there are few clues there as to when precisely this image could have been taken (other than it being after the lithium hydroxide conversion), so we are reliant again on the position of the terminator and satellite analyses. Figure 4.5.23 below shows the image from magazine 60 (Source: AIA), and figure 4.5.24a & b shows the satellite analysis.

Figure 4.5.23: AS13-60-8726 (Source given in text).

Figure 4.5.24a: AS13-60-8276 compared with ESSA (top left), ATS (centre left) and NIMBUS IR (centre right) satellite images, bottom row: 3D reconstructions using digitally restored ESSA (centre) and NIMBUS IR (right) satellite data. Stellarium estimate of time at terminator above. Green arrow as in figure 4.5.22.

Figure 4.5.24b: AS13-60-8276 zoomed and cropped to compare with NIMBUS IR image over Canada.

At the risk of pointing out the obvious (again), there is a degree of overlap between this image and the previous one. The 'speech bubble' cloud identified by the green arrow in figure 4.5.22 has now been split by the terminator line, and the north American mainland can be made out to the west of it. The more detailed NIMBUS IR image shows excellent correspondence with the Apollo photo over Canada.

Using this terminator line Stellarium times this image as roughly 22:30. The ATS image is till the 15th, and the ESSA image is also dated that day. The ESSA pass covering the Atlantic seaboard is track 2, which translates to orbit number 5163, commenced at 16:07. By this time in the journey the CSM and its attendant LM had just passed into the Earth's gravitational sphere of influence and were beginning to accelerate. The crew were also preparing for a mid-course correction burn.

While there are no more images to be used from magazine 60, there were still other magazines being used. Magazine 62 features image AS13-62-8977, which can be seen in figure 4.5.25 (Source: AIA ).

Figure 4.5.25: AS13-62-8977. (Source given in text)

It is always a source of amazement that a figure such as the photograph presented above can contain all the information needed to repel a conspiracist's argument. Ostensibly containing nothing, this photograph, and countless like it, contain sufficient detail of the Earth's weather systems to prove that they were photographed at the same time, or at least within a few hours of, a satellite in orbit much much closer to the subject. Figure 4.5.26 shows the ESSA satellite in comparison with this Apollo photograph.

Figure 4.5.26: AS13-62-8977 in comparison with ESSA satellite image and 3D reconstructions of ESSA and NIMBUS IR data, and Stellarium estimate of time at terminator.

The terminator is falling across the west coast if the USA, and this allows the time of the photograph to be estimated at 02:30, which must therefore be on the 16th.

The main feature on this photograph is obviously the large sweep of cloud that has been a persistent feature over the entire mission, and this has extended from the relatively tight curl centred over Alaska to a much broader sweep. Despite the blurred image, the large swathe of wispy cirrus clouds off Baja California are still very much evident. What is also apparent is that the weather patterns identified by the blue and cyan arrows are noticeably further apart in the ESSA image. Although this may be a product of the angle at which the Earth is being viewed and the distorted perspective of the satellite composite's projection, but it could also be that the weather has moved on between the satellite image's exposure and that of the Apollo photograph.

ESSA's most representative terminator orbit is track 4, which runs along the west coast. This would be pass number 5165, which commenced at 20:07. Examination of the records show pass 5166 is not listed in the data catalogue, and this is either because of some technical problem and data from the surrounding orbits has been used to fill in the gaps (there is a degree of overlap), or it has been missed when generating the list. If the latter is the case, it should have commenced at around 22:00, over 4 hours before the Apollo image was taken. Pass 5167 started just after midnight on the 16th.

The final image that attributable to the ESSA composite from the 15th and its attendant satellite analysis are shown in figures 4.5.27 & 28 respectively, and involves AS13-62-8993.

Figure 4.5.27: AS13-62-8993 (source AIA)

Figure 4.5.28: AS13-62-8993 compared with ESSA and NIMBUS satellite images. 3D reconstruction of digitally restored ESSA data and Stellarium estimate of time at terminator

The land in the centre of the image is the Indian sub-continent, with Arabia on the western Horizon. The bulk of the visible cloud mass is sweeps over the Himalayas before meeting with another weather system crossing northern India from the Indian Ocean. The terminator line falls roughly across Bangladesh on the coast, and this gives an estimated time for the image of 12:30 on the 16th.

ESSA's pass over this part of the world is best represented by orbit 5171 (track 10, which intersects the Bangladesh coastline), commencing at 08:09 on the 16th. At this point in the journey, the crew were busy dealing with repeated problems with one of their batteries, and preparing for the final course correction that would put them in the correct alignment for re-entry.

Once ESSA's satellite passes over eastern Africa, it starts a new page, and any images taken by Apollo will therefore be referenced by an ESSA composite labelled the 16th.The first in the final day's images is AS13-62-9012, (figure 4.5.29). The image shows another development in the life of the weather system that has lain off the Europe and north Africa over the course of the mission, and the position of the terminator gives an estimated time of the Apollo photograph of around 18:00. The satellite image used is dated the 16th, and the analysis in figure 4.5.30 demonstrates that this is the appropriate date for it.

Figure 4.5.29: AS13-62-9012 (source: AIA)

Figure 4.5.30: AS13-62-9012 compared with ESSA satellite images and Stellarium estimate of time at terminator.

The weather front identified by the green arrow is very obviously the same one picked out in numerous previous images, but is also obviously a development of that system and not a reproduction of it. There are, as is often the case, subtle differences between the satellite images and the Apollo photograph that are indicative of a time gap between them. Several more images after this, up to AS13-62-9034 show a similar but slightly rotated view.

ESSA's best path covering the photograph is track 13.In this case this would be orbit 5174, commenced at 14:05 on the 16th.  The crew are now 24 hours away from a safe landing and are going through the housekeeping and entry procedures that will see them through those final hours.

The final image of Earth in magazine 62 is AS13-62-9038 (source: AIA). On the next page, figure 4.5.31 shows this image as shown in the Apollo Image Atlas, and 4.5.32a and b shows the analysis of the weather patterns in it. The terminator line is now runs down through the centre of the north Atlantic, clipping the eastern coast of Brazil. This places the time of the photograph at roughly 20:45, and as the cyan, green and blue arrows point to the same weather systems shown in the previous image, the Apollo image must, therefore, be from the 16th of April.

Figure 4.5.31: AS13-62-9038. Source given in text

Figure 4.5.32: AS13-62-9038 compared with ESSA satellite images and Stellarium estimate of time at terminator. Blue, green and cyan arrows as in figure 4.5.27.

The terminator line is now runs down through the centre of the north Atlantic, clipping the eastern coast of Brazil. This places the time of the photograph at roughly 20:45, and as the cyan, green and blue arrows point to the same weather systems shown in the previous image, the Apollo image must, therefore, be from the 16th of April.

The ESSA track that covers the central Atlantic around the terminator line is number 2, which means that the most representative orbit is number 5176, which was commenced at 17:05 on the 16th. As usual, the most obvious explanation for the high degree of correspondence between the Apollo & satellite images is that they were taken at roughly the same time, one from space, one from low Earth orbit.

The next photograph is one that only emerged recently after an enquiry on collectspace.com, where contributor LM-12 asked for the location of several ‘missing’ Hasselblad magazines recorded in inventories but not found on any of the usual Apollo related websites.

LM-12 mentioned magazine 63 from Apollo 13, and a quick search revealed that half a dozen images could be found at the Gateway to Astronaut Photography. Close examination of the photographs revealed that they were all of the same view taken with different exposure settings. One of these photographs is shown below in figure 4.5.33. Alongside the image is a mock up of a lunar module interior, in which can be seen the panel and equipment details shown reflected in the window through which Earth has been photographed. The simulator view has been rotated to match the view seen in the Apollo image.

Figure 4.5.36a: AS13-59-8492 (source: AIA)

Figure 4.5.36b: AS13-59-8492 compared with ESSA satellite images and Stellarium estimate of time at terminator.

As with the previous analysis, the main land mass visible is that of the Indian sub-continent, and there are a number of similarities between the two photographs. There are, however, subtle differences. The terminator line here crosses the coast of Vietnam, meaning it was taken before the previous one in terms of a single rotation (Stellarium estimates a time of 11:00). The concavity of the terminator line has increased which means that there has been a change in the apparent phase of the Earth, at least in terms of the view from the Apollo 13 craft, the crescent appearing narrower than the preceding day's photograph.

There are also clues in the shape of the cloud systems. While there is the same band of cloud covering the Himalayas, the green and blue arrows point to bands of cloud that do not show on the previous day's photographs of the area. The land either side of the broad swathe of Himalayan cloud is considerably clearer than in the photograph taken on the 16th.

ESSA's image, labelled the 16th, still covers this rotation of the Earth, and the most relevant orbital path is number 5184 (track 10), which was commenced at 09:08 on the 17th.

The crew were now only 48000 miles and 7 hours from a safe landing, At 136 hours into the mission (11:15), they ask about settings for black and white film for the upcoming separation from their CM, so the camera was around at this time too. 10 hours earlier, there was a considerable discussion about what cameras were available for photographing the separation manoeuvres, and some concern at the degree of misting on the windows that might interfere with it. This misting is visible on some of the photographs in other magazines.

Speaking of separation manoeuvres, we have one more set of images to look at.

At 16:43 on April 17th the LM Aquarius was cast adrift from the CM on the last lap of their journey home. A series of images was captured of that separation, which occurred just over 11000 miles about the Earth. Sharp-eyed contributor to collectSpace LM-12 spotted that reflected in the LM window was Earth. Figure 4.5.37 shows the best of the images (AS13-59-8555), with a close up of the window in question.

Figure 4.5.42: AS13-60-8588 compared with German (left) & NOAA (right) synoptic charts.

Again, as with preceding sections no claim is made to any great degree of meteorological expertise, and those more expert are welcome to provide their own views as to which fronts correspond to which cloud masses. The front over the gulf seems simple enough to identify, and the German chart even shows the curl of the cloud band off the east coast.

Although less obvious as a band of cloud, the stretch of clear ocean above the front marked in yellow seems to match up. The blue arrow (not shown on the NOAA chart) would appear to correspond with the system off Alaska.

There is, again, no inconsistency in the meteorological charts available and the weather patterns displayed in the Apollo image.

The next brief examination of meteorological charts is for April 14th. The two images to be used have already been examined in the previous section and show the Atlantic, with a small portion of the Eastern US seaboard (AS13-60-8601), and the Pacific ocean  (AS13-60-8716).They can be compared with the NOAA and German synoptic charts, and this is done in figure 4.5.43.

Figure 4.5.43: AS13-60-8716 (top left) and AS13-60-8601 (top middle) compared with German (bottom) and NOAA (top right) synoptic charts. German data is at 00:00 on the 14th, NOAA at 12:00 on the 14th.

It should be noted that there is a difference of opinion as to whether there is a front associated with the depression over the Rockies between the NOAA and German charts, but this area isn't covered by either of the images so it is difficult to suggest which is correct. It is possible that the time difference between them accounts for the difference in interpretation, their being some 12 hours apart.

The other fronts are clearly visible in the photographs, although it should be acknowledged that the cloud pattern off Florida is more difficult to ascribe accurately. It is the contention here that the cyan arrowed front matches that on AS14-60-8601, and the clouds that connect with it across the Atlantic are those from the magenta arrowed front. The author is always open to other explanations.

One final day's synopses will be examined before moving on to study Apollo 14, and that will be the final day for which Apollo images are available: April 16th. AS13-62-9038 and AS13-62-9012 cover the western and eastern Atlantic respectively, and German & NOAA charts should cover both (figure 4.5.44).

Figure 4.5.44:  AS13-62-9038 (top left) and AS13-62-9012 (top middle) compared with NOAA (top right) and German (bottom) synoptic charts for April 16th 1970.

As with previous synoptic examinations, there is no discrepancy between the synoptic data collected on the ground and the Apollo images taken in space. The most reasonable explanation for this has been made many times: the Apollo images were taken from space, on the days they have always claimed to have been taken.

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The rotational movement over the sequence is undeniable.

There is a considerable time lapse between these images ant the next photographs of Earth. The next image in Magazine 60 (AS13-60-8601) is from the 14th, all other images showing it appear after it has passed around the far side of the moon. This particular image will be discussed at the appropriate point in the sequence of images taken on the 14th. Magazine 61's images featuring Earth all appear after those showing a receding Moon (and are therefore obviously on the way home), Magazine 62 shows a few images at the start of the film with a relatively large crescent Moon, after which there are a few images of a very small crescent Earth, and more are shown towards the end of the magazine after a sequence of far side lunar images. Magazine 59 shows pictures of a relatively large crescent Earth immediately before images taken after the damaged service module was cast adrift. These images of Earth will now be presented in the order that it has been calculated that they were taken.

The first in the sequence is AS13-62-8886, which occurs after the aforementioned set of images of the Moon through the spacecraft window. Figure 4.5.10 shows this image, and 4.5.11 the satellite analysis.

Figure 4.5.33: Left - AS13-63-9045 (Source), Right - Apollo 14 astronauts in a Lunar Module simulator as seen through one of the windows, rotated to match the Apollo 13 view (Source).

Before dealing with the view of Earth, it’s worth pointing out that there are clear shots of the interior of the lunar module in the Apollo 13 photograph. I’m sure someone idiot will point out that the other photograph I’ve used is a simulator blah blah that’s how they did it drone drone, but what they have to then get around is the fact that there is a large planet Earth in the picture. Speaking of which, let’s have a look at what we can see on it, and when it might have been taken.

The shape of the crescent suggests very strongly that it belongs in the closing stages of the mission, so the search began on ESSA images from that part. The weather systems we are looking for turned up on the satellite view taken on the 16th, and this is shown below with a rotated and cleaned up version of the Apollo 13 photograph in figure 4.5.34.

Figure 4.5.34: Zoomed and cropped version of AS13-93-9045 compared with ESSA satellite image dated 16/04/70 and Stellarium view of Earth set at 06:30 on 17/04/70

The first point of identification was the ‘y’ shaped system identified in the red arrow, only faintly visible on the Apollo view, but once that was spotted the rest fell in to place. The key to the time is the system shown by the magenta arrow on the east coast of Australia, placing the time at around 06:30 on the 17th.

There isn’t much confirmation of this in the mission transcript - the crew were supposedly on a rest period after some fairly intense technical exchanges aimed at getting them home in one piece. They complained that it was too cold to sleep, and one of them must have used a quiet moment to snap a photograph of home. It’s worth pointing out the green arrow, which identifies Tropical Cyclone Isa.

It’s often documented that Apollo 13 witnessed a tropical storm on re-entry, and that this was Tropical Cyclone Helen - a storm that they were already aware of before the incident as it was in a potential landing site in an unexpected early abort. These things were always planned for! Despite these claims there is no actual mention of it by the crew other than in passing when discussing their landing zone, not re-entry. Here’s the exchange between Jack Lousma as Capcom and LMP Haise:

112:38:39 CC: The weather prediction for your landing area is still good; 2000 scattered, high scattered; 4-foot seas, 15-knots wind. There's a hurricane 500 miles to the west, which doesn't pose a problem.

112:39:02 LMP: A hurricane or a typhoon?

112:41:24 CC: Belay my last. It's degraded to a tropical storm.

The time for that comment is about 11:45 on the 16th - quite some time before this photograph. The storm threat is discussed in this Universe today article, complete with photograph of Mission Control staff poring over a weather map, and one member of that team discusses it in the article. It’s possible that the discussion is buried somewhere in the tape loops here, but it’s very likely that reports of the crew seeing Cyclone Helen are based on remembering scenes in the Apollo 13 film.

An interesting diversion is provided by the image used in that Universe Today article, which is also available in slightly higher quality here. Figure 4.5.35a shows the image in question, which is captioned as showing the flight control team examining a weather map to when working out landing zones.

Figure 4.5.18: AS13-61-8867 (source: AIA) and the zoomed and cropped Earth, level adjusted to remove noise.

There isn’t any point in repeating the satellite analysis, which is obviously going to be the same,  so we can look instead at the differences along the terminator that will allow confirmation of the time it was taken. Figure 4.5.19 shows a comparison of the terminator area by the cloud pattern picked out by the red arrow in figure 4.5.17.

Figure 4.5.19: Area along the terminator from AS13-61-8864 (left) and AS13-61-8867 (right).

It’s pretty obvious that there has been some rotation between the two images, the question is ‘how much’? The key to working this out is the area of cloud over south-western Australia, which is almost on the terminator in the second image. This suggests a time of around 08:45 GMT on the 15th, as indicated in figure 4.5.20

Figure 4.5.20: Terminator region showing Australia from AS13-61-8864 )bottom left), AS13-61-8867 (bottom right), ESSA (top left) and Stellarium estimate of time at terminator (top right).

Figure 4.5.37: AS13-59-8555 and a close up of the LM window.

So, can we work out where we are looking? Well, we have a precise time and we have a precise altitude. We also know, thanks to the mission report, the precise position above Earth of the LM at separation (1.23 S 77.55 E), which means we can narrow it down quite a lot. Her are two views of Earth from Fourmilab showing how it looks from the moon, and from the LM separation position.

Figure 4.5.38: Fourmilab Earthview of Earth at 16:43 on 17/04/16 from the Moon (left) and from the separation point at an altitude of 11250 miles.

The terminator is running down the centre of Africa, and realistically not much should be visible in daylight other than eastern Africa and perhaps a little of Europe.

This illustration from Universe today (figure 4.5.39) indicates that the view is more likely to be of equatorial Africa rather than Europe given the approach Apollo 13 took to its eventual landing site. However it’s also possible that the trajectory could have pointed the camera towards the north or south!

Figure 4.5.39: Ground track of Apollo 13 from re-entry to splashdown, as shown in Universe Today.

The track is looking all in the Southern hemisphere, and it the trajectory would again imply that the view reflected in the LM window is likely to be around the equator.

So, we should have a view of equatorial African reflected in the LM window. Let’s see how that turns out. First of all, we need to invert the view of Earth to stop it being a mirror image, and we can also help ourselves in identifying any weather patterns by stretching the view a little.

Figure 4.5.40: Earth seen in the LM window. The view has been level adjusted and sharpened, and the view on the right perspective corrected.

Can we realistically identify weather patterns here? Well, to be honest not with any great degree of certainty, particularly as we don’t really know how wide an area we are looking at. The width of the sunlit area here pretty much rules out anything other than central and sub-equatorial Africa, and the amount of curvature on show suggests a relatively small field of view, so let’s have a look at that the data from ESSA’s shots on the 17th.

Figure 4.5.41: ESSA image from April 17 of Africa, and a zoom and crop of south-west Africa.

As I said, nothing I would bet my house on, and I base my judgement on logical deduction rather than precise identification, but for now I am pinning my hopes on the the area I’ve zoomed into above. It’s in the right place and contains the right sort of broken cloud. It’s just a shame that the satellite images aren’t as clear cut as in other examples.

Even if I am wrong in my estimate , what is interesting is that even in images reflected in a lunar module window there are clear details of the Earth and its weather systems, and the clouds even have shadows underneath them - such is the level of detail.

Apollo 13. Around the moon and home again, with the photographs to prove it.

4.5.2 Meteorological evidence

The same sources used for previous sections are again available here (the reader is referred to those sections if they wish to check them themselves), but as with Apollo 12 the ever diminishing crescent of the Earth and the fact that the majority of photographs show areas not covered by the synoptic charts limits the number of possible comparisons.

April 11th did, at least feature good coverage of North America, which allows us to revisit AS13-60-8588, Figure 4.5.42 shows the NOAA & German synoptic charts for April 11th compared with that NASA image.

Figure 4.5.0b: TV still from Apollo 13 Earth orbit broadcast compared with a crop from AS13-60-8588 and an ESSA satellite view. Below this is a compilation of screenshots from the broadcast

The ESSA image does identify clearly the broad swathe of cloud crossing the Gulf, and while the elapse of three hours means there is a difference in the exact configuration of clouds between the photo and the TV still, there are some similarities between them, notably thin strands of cloud trending north-south alongside the northern edge of the much broader west-east cloud band. The red arrow shows areas where the features are very similar

After TLI, the crew did the usual retrieval of the LM from the SIV-B, and this procedure was recorded as part of a TV transmission. It's not clear whether this live transmission was purely for NASA's benefit as it covered a fairly dull procedure as far as the viewing public was concerned. The footage is available here: Apollo 13 footage, and at 3:48 in we hear the words “Is that the world there” in response to a comment from Capcom about the view of Earth being shown. This timing is derived from the mission transcript (ALSJ).

Although it is not a full Earth view, the presence of images preceding it of the docking manoeuvre means that the craft was no longer in Earth orbit. Figure 4.5.1 shows a screenshot of that footage together with ESSA 9 and ATS-3 views of the Earth on April 11th.

Figure 4.5.4: AS13-60-8588 compared with ESSA (left top & bottom) and ATS (below left). Below right is a 3D reconstruction of digitally restored ESSA data. Stellarium estimate of time at terminator to left.

Figure 4.5.6: AS13-60-8590 compared with ESSA (top left) and ATS ( bottom left) satellite images. Bottom rigt is a 3D reconstruction of digitally restored satellite data. Stellarium estimate of time at terminator is to the left. Cyan, magenta and red arrows are the same as on figure 4.5.4.

Figure 4.5.11: AS13-62-8886 compared with ESSA (top left) and ATS (bottom left) satellite images, and 3D reconstruction using digitally restored ESSA data (bottom right)with Stellarium estimate of time at terminator to the left.

Figure 4.5.0a: AS13-60-8578 compared with ESSA image from the same day (centre) and 3D reconstruction using modern data (right)

The thin cloud is obviously equally wispy on the satellite images, and the gaps in the cloud match up well. If you’re a flat Earther, first of all well done for being able to read, and secondly note the nice curve to the globe on the horizon.

The TV image, taken here from a Dutch broadcast, shows a broad swathe of cloud. To get an idea of where we are in the world, the crew discuss their location with the ground and they work out that they are crossing the Gulf of Mexico off the southern US coast:

001:42:10 Swigert: Okay, Joe. It appears like that we've crossed out into the Gulf of Mexico here, and I've got a peninsula or an island that's down there.

A colour version of the broadcast can be found here.

The time stamp on the transcript tell us that this broadcast was made at 20:50 on the 11th. While it’s not possible from that image to tell exactly where we are, we can see of what we can see is consistent with other images. Figure 4.5.0b below shows a still from the broadcast together with an ESSA view of the area, and a close up from AS13-60-8588 which (as will be demonstrated below) was taken about three hours later.

Figure 4.5.35a: Flight control staff examining a satellite image. Source.

Is it possible to work out which satellite image is being used? Well, if we rotate the image and stretch it so that it’s more like the view they have of it it, it looks like the view presented in figure 4.5.35b, which is shown with the actual satellite image that was commenced on April 14th, but completed on April 15th.

Figure 4.5.35b: Comparison of ESSA image taken on April 15th with the one in figure 4.5.35a.

The small bright spot of cloud is Tropical Cyclone Helen, as pictured sometime around 04:00 on the 15th. The main concern for the forecasters was that changing the location of the landing had implications for when a course correction burn could be carried out, and this was not a mission where resources were limitless. By the time that satellite image had been taken they were confident that the chosen spot would be OK and that they could use re-entry procedures to help avoid the area. As Helen’s track still wasn’t absolutely certain and they organised lots of reconnaissance flights to make sure - as detailed in this report. Indeed the New York Times was already reporting on the 15th (and therefore knew about it on the 14th) that:

“A tropical storm named Helen near the New Hebrides about 1,700 miles away was being watched closely by Navy weather experts. It was not expected to interfere with the planned recovery.”

As for the Apollo 13 the movie, as tension builds before re-entry RETRO (the flight control member responsible for all matters re-entry) alerts Kranz to the storm in the landing area (which we now know to be a hefty bit of dramatic licence). The camera pans down to what is supposed to be a satellite image on his desk. Apart from the fact that the image is colour (no colour satellites existed at that time), the photographed used is actually form Gemini V in 1965 (see figure 4.5.35c). Rather than showing the south Pacific, its actually the Hawaiian islands.

Back to timing the Apollo image, we do get a small clue that confirms that Australia should be in shot at the time I suggest it was taken. About an hour after Stellarium’s time capcom tell them that they will shortly be handing over to Honeysuckle Creek on Australia’s east coast - confirming that the Pacific would dominate their view of Earth at the time the photograph was taken. As for the satellite image, the visible area is best described by track number 7, or orbit 5181, which began at 03:02 on the 17th.

It’s also worth pointing out that the crescent on the Stellarium view is much narrower than that of the Apollo image, which is again consistent with it being cislunar space.

It’s are remarkable testament to the consistency of the Apollo record that a photograph that very few people even know exist, and equally few people have seen, can reveal details that match what should be visible. Yet another one in the eye for Apollo deniers.

The final image in this sequence is from a so far unused magazine, AS13-59-8492.

It occurs as part of a short sequence of images immediately before photographs of the jettisoning of the damaged service module part of the CSM, which occurred at 13:14 on the 17th. Prior to this are a number of photographs taken from within the CSM. The Apollo image is shown in figure 4.5.35, and the satellite analysis in figure 4.5.36.

Figure 4.5.35c: Still from ‘Apollo 13’ and Gemini V image S65-45616_G05-H.