4.7.8 - Apollo 15 Day 8 - On the ground
Day 8’s first view of Earth is very similar to day 7’s, in that it is brief and not very interesting.
The TV view of Earth took place at Station 10 during EVA-3. The Earth view was pretty much achieved by accident and is seen at the start of the TV footage, which commenced at roughly 11:50 on August 2nd.
The camera is focused on Earth at the start of the footage but is repositioned so quickly once it is realised that it is stuck that we get nothing we can use to provide a sense of distance above the horizon. All we can do is compare what we should be seeing with what is shown, as indicated in figure 4.7.8.1.
Figure 4.7.8.2: TV still of Earth compare with Stellarium view at the same time. Source.
Once again the Earth’s phase is entirely consistent with what should be on view, even if we can’t make out any actual details on it.
For the next full analysis we visit a new photographic magazine. AS15-88-11976 occurs two thirds of the way through magazine 88. The magazine starts on the lunar surface, but this image occurs immediately after a photograph of the CSM during rendez-vous. We therefore have an earliest possible time for the image of 17:11 on the 2nd of August.
The LM & CSM were docked two hours later at 19:10. We can tell that the photograph was taken inside the LM because we can see, reflected in the window through which Earth is taken, the docking window (see figure 4.7.8.3.
Barring a quick tourist shot while transferring equipment and samples, we therefore have a maximum 2 hour window within which this image was taken. Realistically, we can narrow that down further given that they had to ascend to orbit and rendezvous with the CSM, only beginning station-keeping (when photographs of the CSM from the LM were taken) at 18:49. 18:57 is the time that capcom reminded the returning crew to take the photographs of the CSM.The lunar module was finally sealed off at 22:!4. Let’s see if the evidence supports this. Figure 4.7.8.4 shows the satellite comparison.
Figure 4.7.8.3: Full image and docking window detail in AS15-88-11976.
Figure 4.7.8.4: AS15-88-11976 compared with ESSA imagery from August 2nd. 3D construction using that data set at 18:57 (above right) and at 22:14 (far left). The Apollo photograph ash been contrast and brightness adjusted to bring out detail.
The figures given by the timeline for the mission show that the Earth should have been showing the Atlantic, and at least some of Africa. The configuration of the Earth as seen from the Moon also means that the southern Hemisphere is more prominent than the north, placing north Africa at the top of the illuminated crescent. The arrows are identifying clouds bands either side of the equator in the ITCZ, and what appear to be low lying fog banks on Africa's west coast.
The ESSA 9 orbit covering this part of the Earth would have been commenced at 15:01 (track 1, orbit 1083), so ESSA's satellite image was taken at around the right time. SkySafari shows where the terminator would be at the time the image is recorded as being taken, and there are cloud shapes in the right place and consistent with the weather patterns visible from ESSA. It would be preferable to have crystal sharp images, but even without them the available data corroborate the version of events that says the Apollo 15 crew met up with each other in lunar orbit on August 2nd just before 19:00 GMT.
It’s worth noting that the Photography Index records the photograph as bring taken during Rev 49, and suggests that the CSM can be seen in the window. My opinion is that it is actually the camera lens rather than an out of focus CSM, but either way, we know that this matches the other evidence.
The 3D construction representing the latest possible time the photograph could be taken does have areas that could equate to the Apollo photograph, but it is (to my mind) less likely.
The next image was taken on the following day, and an increasingly thin crescent makes this task even more difficult. We’ll see how we do.