Figure 4.4.28: GAP scan of image AS12-
Figure 4.4.29: Main image -
Timing this image is difficult as there is little in the way of landmass visible to pinpoint the terminator's exact location. The absence of land mass does allow a certain amount orientation in Stellarium. Australia does not appear until 5 am, and California disappears at 1 am, so the image must fall between these two times. The yellow arrow points to a cloud system that falls on the 170 degree longitude line, and if it is assumed that this is the same one picked out on the Apollo image, them the western horizon is at 170 degrees. If this is the case then the terminator falls roughly along the line picked at 140 degrees longitude in the northern hemisphere, a line which also falls on Alaska. As Stellarium's cloud patterns are fixed and there is a spiral one over Alaska, its estimate of 01:30 seems reasonable, and coincides well with the estimate worked out in the preamble to this image's analysis.
Both of the satellite images chosen are from the 18th, as their orbital passes are closer to this time than they would be in images taken on the 19th. ESSA's best orbit is 3318 (track 6) which commenced at 23:01, & NIMBUS' orbit 2930 on the daylight IR image is the most appropriate one for the Apollo picture, and this commenced at 19:48.
Another film magazine contains an image of Earth before separation but is definitely from lunar orbit: number 51. This roll starts with a large number of 'face on' images of the lunar surface, placing it firmly in lunar orbit. AS12-
Figure 4.4.30: AS12-
Figure 4.4.31: AS12-
The key weather systems here are the two identified by the green and cyan arrows off the western coast of Australia. The system picked out in blue is just off the Sumatran coast, which also helps to narrow down the location of the terminator. It is unfortunate that this weather system crosses the boundary between two day's ESSA data, and more unfortunate still that there is not as much overlap between the two day's data shifts in terms of longitude (so that we can't use the data from the next day to corroborate), but you can't have everything. The NIMBUS view does show that we have the correct weather system in our sights. The best estimate for the terminator position here gives a time of approximately 11:30 on the 18th.
ESSA's best orbit from this image is orbit 3310 (track 10) which was actually commenced at 08:09 on the 18th, while NIMBUS' best available orbit is 2922 which commenced at 05:25 on the 18th. The orbits covering Australia exactly do not feature clear images, or are absent.
A time of 11:30 would put the still joined spacecraft in lunar orbit after the second circularisation burn. This is supported by the first few images in the magazine, which shows an initially lit lunar surface over Mare Nectaris (on the eastern near side), followed by darker frames, then a brightly lit one of Mare Nubium in the south-
Immediately after separation of the LM from the CSM in magazine 47 is a sequence of Earthrise images. As magazine 47 went to the lunar surface, and didn't complete more than one complete revolution as it did so, timing the image is much simpler than the preceding two, It is also helped by the astronauts' chatter in the LM as they discuss the upcoming Earthrise and making sure that they captured it (see the LM Voice transcript) at 4d13h43m, or 109:43 hours MET, or around 06:00 on the 19th – 55 minutes before landing.
Figure 4.4.32 shows one of these images, and figure 4.4.33 the satellite comparison.
Figure 4.4.32: GAP scan of AS12-
Figure 4.4.33: AS12-
As with the previous analysis, the key to this one is the weather system off south-
ESSA's best track over this area is again number 8, and orbit 3321 on the image dated the 18th was commenced at 05:07 on the 19th. For once, the NIMBUS night time orbit gives the best visible data (and the day time images are absent!), and pass number 2938 on the 19th was commenced at 11:15 – 5 hours later than the Apollo image but providing a good match.
No more images of Earth from other orbits are available on this magazine, and none were taken by the crew on the lunar surface. By this time it was becoming an increasingly thin crescent and would not have presented much of an object in the sky.
While Bean & Conrad set off for the surface, Gordon continued his orbits, and took a further 3 sequences of Earth images in magazine 51. The first of those occur immediately after the separation images. As separation occurred over crater Ptolemaeus in the centre of the near side and the photographs contain no sign of the Moon, it is likely that the Earth image was taken by looking straight back towards home just after separation.
Of the two available, the image chosen is AS12-
Figure 4.4.34: Gap scan of AS12-
Figure 4.4.35 AS12-
The most obvious point to make about figure 4.4.35 is its similarity to figure 4.4.33. Indeed the satellite image sections are the same, so the ESSA and NIMBUS timings cited earlier will also be the same for this analysis, and there isn’t much need for an additional 3D reconstruction.
The only significant difference between the two Earths is that in this one the globe has revolved slightly further, exposing more of Australia (see figure 4.4.36), something that proves it is not merely a copy of the Earth seen in the Moon bound photograph. This rotation adds roughly 15 minutes to the time of this image compared with the previous one. The absence of any Moon at all in this photograph also confirms that it was taken some time after the Earthrise greeted so exuberantly by Bean and Conrad.
The relative sharpness of this picture also allows a degree more certainty in identifying the weather patterns on the satellite photographs compared with the Apollo Earth, and has helped to confirm the analysis given for figure 4.4.33.
After separation, the CSM continued to orbit and captured another 2 sequences of images. The first one consists of two photographs of a crescent Earth with no lunar surface visible. This is not an Earthrise sequence, but the CSM has obviously passed around the moon at least once since the preceding image, as there are photographs of the lunar surface in various stages of light and shade, and Mare Nubium on the east followed by far side craters such as Mendelev.
The best quality image is AS12-
Figure 4.4.36: GAP scan of AS12-
Figure 4.4.37: Main image -
The ESSA image used is again from the 18th, and the most obvious cloud that specifically pins it down to that day's image is the one highlighted by the yellow arrow, and as with previous images once the most obvious cloud is identified the rest fall into place. Track 10 covers most of the image's daylight portion, and this corresponds to pass number 3302, commenced at 07:03 on the 19th. The NIMBUS image is the daylight IR data from the 19th, and pass 2935 covers the coast off western Australia up towards India. This was started at 04:42.
Looking at the top of the Earth's crescent in this image reveals a landmass, and it is this that allows the time at terminator to be picked out. The clouds identified by the red arrow are over that landmass, and which puts the terminator position as at roughly 10:30 – about 3 orbits later than the preceding photograph. As it is not an Earthrise image it could have been taken at any point in the nearside part of the lunar orbit, but there is at least one orbit between the previous image analysed and this one. 10:30 would put the mission elapsed time at just over 114 hours 10 minutes, or 4d18h in. We know that the CSM was over the daylight side at that time, because at 4d18h23m Dick Gordon announces that he has sighted the LM through the sextant.
The final Earth sequence (but not the final Earth image) to be examined was taken immediately after the preceding one. AS12-
The image is shown in figure 4.4.38, and examined in 4.4.39.
Figure 4.4.38: GAP scan of AS12-
Figure 4.4.39: Top image -
There are no intervening pictures of lunar surface to act as a guide for how many orbits have elapsed between AS12-
Consequently, there is not much difference in the satellite image timings for the visible part of the Earth's surface. NIMBUS orbit 2936 is the major part of the daylight IR image used, which commenced at 06:29 on the 19th. The magenta arrow identifies clouds imaged at 06:57 by NIMBUS. ESSA's companion pass is 3323 (track 11), which commenced at 09:08. As usual, two satellites show images from a specific day with specific cloud formations unique to that day, and that match the Apollo image. The WMO image is identified as having been taken at 03:49 GMT.
We have one more image from the moon to examine, this time from lunar orbit taken by the 16mm camera using magazine P. Magazine P starts off with poor quality footage from the lunar surface before switching to footage obviously taken from orbit. The movement of the camera strongly suggests it was taken during the lift off sequence. We know, therefore, that the footage has to have been taken after 14:33 on November 20th. As Earthrise can only have been almost ¾ of an orbit later, so let’s put it conservatively at 15:30. Figure 4.4.40 shows the still, compared with the Stellarium view of Earth at the same time. See here for suggestions that it also contains Jupiter.
Figure 4.4.41: AS12-
Apollo 12 did experience a unique solar eclipse as it passed a point where the Earth completely blocked out the sun. There are, however, a couple of pointers to the fact that this is not a total eclipse. One fact is that by the time of the actual 'eclipse', the 24th, the crew had run out of colour film, and could only shoot the event in black & white. The other major clue is obviously present in the photograph: lens flares. The sun is off to the bottom of the picture (this is even more obvious in subsequent photographs in the magazine but they don't show the Earth crescent as well), so it can't therefore be behind the Earth!
So when was it taken? The image is actually showing the Earth as a crescent continuing to change phase naturally as it has throughout the mission. Figure 4.4.42 shows Stellarium views from the Apollo 12 landing site at noon from the 20th to the 24th of November, illustrating the changing phase from a lunar perspective.
Figure 4.4.42: Stellarium views from Apollo 12's landing site of Earth at noon from 20-
Looking at these crescent views, the perspective most like that in the Apollo image is that of the 21st, probably later than the 12:00. The whereabouts of Apollo 12 by the 21st depends on when it was taken, as early on in the day it was involved in landmark photography while still in orbit, but at 20:51 it performed a TEI burn.
The size of the Earth in the photograph suggests it is much closer to the CSM than the views given in orbital images featuring Earth. The tricky part now is to identify any weather patterns. We have a very small amount of visible cloud, but at least a 24 hour window within which to search. The ESSA image dated the 21st will cover the globe from around noon on that day to noon the next day, so the clouds we are looking for should be visible on that image somewhere.
The visible cloud system consists of a large but well defined tropical cloud mass, (at that time of year, the centre line through the widest part of the crescent should roughly equate to the latitude 10 degrees south) to the north of which are high altitude cirrus type clouds and to the south an elongated band stretching south-
For once, there will be no guarantee that the exact cloud has been found, but figure 4.4.43 shows the most likely candidate. The clouds arrowed in green are on the line of 10 degrees south, there are wispy clouds to the north of them, bands of clouds to the south. These patterns are particularly evident on the NIMBUS daylight IR image, and the cloud's shape is much more similar to the Apollo image. The pictures from the 22nd bear much less similarity to Apollo, and of course after this the Earth's crescent starts to become much too thin.
Figure 4.4.43: AS12-
The exact time at terminator would depend on how much of Australia is visible. In this case at least some has been assumed, giving a time of around 07:30.
The NIMBUS image pass that covers the terminator line around the main cloud system is number 2959 from the 21st, which was commenced at 23:40 on the 21st, quite a bit later than the Stellarium time would suggest. ESSA's image, although less like the Apollo photograph, would have been started at around 03:04 (pass 3345 from track 8) on the 21st, with the image used having a date of the 20th. The 3D reconstruction of ESSA data would seem to confirm that we are looking at the right place.
We have one final sequence of images of Earth to look at, those filmed by the 16mm camera during re–entry. The footage comes from magazine G, and an example of it can be found here.
According to the reference work ‘Apollo by the numbers’ the Earth entry interface took place at 13.8 degrees South, 173.52 degrees East eventually splashing down at 20:58 on November 24th at 15.78 degrees South, 165.15 degrees West. Figure 4.4.44 shows these locations pinpointed on Google Earth.
Figure 4.4.47: German (left) & NOAA (middle) weather charts from 14/11/69 compared with AS12-
The main frontal system picked out here is the one trending roughly west to east over the Pacific before veering to the north-
Of the images examined in the previous section, the next one featuring any kind of frontal system that are shown on the weather charts is from November 16th, AS12-
Figure 4.4.40: 16mm still showing Earthrise compared with Stelarium view.
What can also be seen in the window is the Landing Point Designator markings on the LM window, which strongly suggests that this is taken from the LM window before re-
05 23 18 58 CDR Here comes earthrise.
05 23 19 O0 LMP ...
05 23 19 01 CDR Too bad we don't have a camera.
05 23 19 02 LMP We do. Where is the earthrise?
05 23 19 05 CDR Right out your window.
05 23 19 06 LMP You take it. I got -
05 23 19 18 CDR It would be better if you took it out your window.
05 23 19 20 LMP It's all frosted, Pete.
Earlier on they had been cursing the 16mm camera’s failure at lift off and it consequently not capturing the landing site as they viewed it from above. That timing works out at 15:41, so m initial guess was pretty good. While the image quality through the badly frosted window isn’t enough to see any detail on the Earth, we can at least see that its phase is completely consistent with what should be visible.
The final image examined from Apollo 12 is presented partly as a piece of detective work, and partly to point out a possible error in the Apollo Image Atlas.
The NIMBUS tile is clearly marked as having been taken at 22:54 on the 24th, while the ESSA data would suggest a time of between 01:00 and 03:00 to image the landing area.
I don’t think there is a clear enough image to determine exactly where we are looking, but the area to the north of the re-
As always, the sources of information are there for anyone to repeat this analysis and draw their own conclusions, but aside from last one where this is a possibility of doubt, all of the preceding images have allowed a considerably degree of precision in identifying when a photograph was taken, and more importantly from where: On a Moon bound spacecraft carrying three astronauts.
4.4.2 Meteorological comparisons
For much of this particular mission, the phase of the Earth, the timing of the photographs themselves and the winter season (the Earth's tilt angling the northern hemisphere away from the lunar viewpoint) mean that the German, NOAA & South African data are of less use, at least for the latter part of the mission.
For the early part, however, we have a few days over which to confirm that the satellites were accurately reflecting the situation recorded by terrestrial meteorologists (and are therefore not fabrications), as well as the ground based recordings providing an accurate representation of the reality recorded by Apollo. The sources for the NOAA meteorological data are the same as those given in the preceding sections, and the German data can be found here: http://docs.lib.noaa.gov/rescue/cd277_pdf/LSN1157.PDF.
The Apollo image for the 14th of November (the first one used in this analysis) does feature enough of North America to allow the use of at least the German & NOAA weather charts. Figure 4.4.47 shows the relevant parts of these two charts compared with AS12-
Figure 4.4.44: Location of Apollo 12’s re-
The footage varies in what it shows, but we do get a clear shot from time to time of the ocean below them. Figure 4.4.45 shows some stills from the footage.
Figure 4.4.45: Screenshots of the Apollo 12 re-
The first thing to suggest is that looking at the trail behind the CM and the horizon in the distance we are still at quite a high altitude here. Can we match up what we’re seeing with any satellite footage?
The archives available for this mission don’t have any images for the 24th, but the US ESSA data recovery project does have an image of the southern hemisphere covering that date, and we can combine two of their images to produce a satellite image covering the re-
Figure 4.4.46: ESSA and NIMBUS images dated 24/11/69 from reconstructed tape data.
The red marker is the re-
Figure 4.4.48: AS12-
The system picked out in green is the one extending across the Atlantic from the Mexican Gulf towards Europe. The large weather system extending south-
An image from the 17th examined earlier can also be looked in terms of the weather charts available (figure 4.4.49). AS12-
Figure 4.4.49: AS12-
As with previous examinations of these meteorological charts from other missions, no absolute guarantee can be given of the accuracy of the author's interpretations, but it doesn't seem unreasonable that the long sweeping frontal system (blue arrow) is the same one in the synoptic charts and the Apollo image. The larger cloud mass over the north-
Apollo 12 then, as with the other missions examined so far, shows a wealth of detail in photographs of Earth that could not have been created in an artist's studio, and accurately portray the weather systems shown on the satellite images for the simple reason that they are photographs of those weather systems, taken from space.
Figure 4.4.26: Main image shows AS12-
These two images were taken relatively close together, as can be determined by nearly all of the identifier arrows being used in both analyses (the cyan one has been used as a link to the next photographs). The first photograph has the west coast of South America just visible, and most of north America, which allows Stellarium to put the time at around 23:00. It is slightly more difficult to see the coast in the second image, but the cloud patterns picked out by the yellow and magenta arrows show that the terminator is just off the California coast, which would give an estimated time for the image of 00:30 on the 18th of November.
The most obvious features are the large circular cloud off Chile picked out by the cyan arrow (and the attendant flecks of cirrus clouds west of that that are visible once the circular feature disappears in to the night portion of the globe), the long finger of cloud stretching from the Antarctic north-
As stated previously, the ATS-
The remaining images on magazine 50 are close ups of the lunar surface, starting with very rounded lunar horizons and ending with much flatter ones, indicative of a space craft approaching the Moon. LOI for Apollo 12 is recorded as being carried at 03:47 on the 18th, so it seems that AS12-
For the next 24 hours the crew are somewhat busy checking out the LM and preparing for separation of the two craft and initiating the descent to the surface. This separation of the crew and their attendant cameras provides two vantage points for the Earth – one from the CSM & the other from the LM. Magazine 47 has a couple of Earthrise sequences before showing images taken on the lunar surface – one taken before separation from the CSM and one after, while magazine 51 shows one image of a distant Earth before separation, and several photographs of Earth taken on different orbits, including an Earthrise.
Pinning down exact timings of the images in these two magazines involves a certain amount of detective work, and we’ll deal with the Earthrise images first. After LOI, the LM pilot entered the LM to perform system checks at around 08:50 on the 18th, finally entering with the mission commander at 00:42 on the 19th, where both crewmen remained. The LM & CSM separated at 04:16 on the 19th. Just after the start of magazine 47 are 4 images of an Earthrise. These occur immediately before 2 images of the CSM taken in to the sun, but after two images of the lunar horizon and a distant Tsiolkovsky – a far side crater proving that the image was taken after LOI.
It does not take a great deal of logical leaps to conclude that the 4 Earthrise shots were therefore taken before this time. Also featured in the images is one of the LM's quad thrusters, which suggests that the photographs were taken while in the LM, and it seems reasonable to assume that this was after all the camera equipment and other gear needed for the landing was transferred. A likely time seems around 105 hours and 41 minutes, which would be around AOS on the final orbit before separation.
The 2 photographs immediately following this short Earthrise sequence feature Copernicus, a prominent near side crater almost completely opposite Tsiolkovsky. Copernicus gets an enthusiastic mention by the crew at 106 hours 30 minutes, but prior to this they report that they were unable to find it, which would seem to confirm the suggestion that it the Earthrise was taken on the final orbit before separation, after their sighting of Tsiolkovsky.
This would give a working estimate of around 02:00 on the 19th for this sequence, and AS12-
Figure 4.4.28 shows this image, and figure 4.4.29 does what satellite comparison is possible.
Figure 4.4.27: Main image -
Figure 4.4.24: AS12-
4.4 Apollo 12 -
(Continued from previous page).
Two final images will be examined from magazine 50 as these are the last before LOI, and occur after the images of the moon discussed above. As will be demonstrated, they were taken relatively closely together, and the second one shows the window frame and glass from the Apollo craft. The images themselves are shown in figure 4.4.24-