4.5.2 - Day 2: Trans-Lunar Coast and the prelude to disaster

The early hours of the 12th are occupied by a period of 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. Thew transcripts record the build up:

007:17:05 Lovell: Roger. We're at that stage now where we're going to take some Earth weather photography. If you're standing by, I have the camera aimed at the Earth right now, and I'll give you a mark when I take the first picture.

007:17:19 Brand: Roger. We copy, Jim. We'll be standing by for the mark. [Long pause.]

007:17:41 Lovell: Okay, Houston. 3, 2, 1...

007:17:45 Lovell: Mark.

The first image was taken at exactly 02:30:45. The next image of Earth in magazine 60 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 shows this image, and figure the satellite image comparison.

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Figure AS13-60-8590, source AIA

Figure 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

The weather system identified by the red arrow is clearly the same as that in figure 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.

The next image was taken just 22 minutes later, so there’s little point in doing a complete analysis of it. However, we can show that it has changed orientation, and that Earth is a genuine, rotating object in space. Figure shows the image, and a comparison of an area of terminator between this one and the one above. As before, Lovell cues us in:

007:39:26 Lovell: Stand by for another Earth weather picture. I'll give you a mark.

007:39:29 Brand: Okay. Standing by, Jim. [Long pause.]

007:39:46 Lovell: 3, 2, 1 ...

007:39:49 Lovell: Mark.

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 the clouds chosen.

There is a much longer gap than was intended between this image and AS13-80-8592, as adjustments to their orientation meant the vie wof Earth was lost:

008:10:46 Haise: And Vance, on that picture, I was all set to shoot it just a little before you called, and the Earth hasn't showed up in the window yet. I don't know if we got too far off the bellyband or what.

but it was resumed again later:

008:41:53 Haise: Okay. Ready for a little count here, Vance, and I'll shoot another picture. We found the Earth again.

008:41:59 Brand: Okay. We'll be standing by, Fred.

008:42:05 Haise: Okay. 3, 2, 1...

008:42:09 Haise: Mark.

008:42:11 Brand: Roger. Copy.

Figure shows the next image in the sequence.

Figure Section of AS13-60-8590 (top left) compared with AS13-60-8591 (top right. Original image far left. SkySafari terminator depiction left. The red line top left marks the terminator position in AS13-60-8591.

Figure AS13-80-8592 and SkySafari depiction

The distinction weather sequence is now much closer to the terminator, but again there isn’t any need to reproduce all the satellite imagery.

Image number 4 in the sequence is shown in figure

009:02:52 Haise: Okay. Stand by for a mark on another picture.

009:02:55 Brand: Okay. Standing by, Fred. [Long pause.]

009:03:09 Haise: 3, 2, 1...

009:03:12 Haise: Mark.

Figure AS13-80-8593 and SkySafari depiction

Next up, AS13-80-8594 (figure

009:26:19 Haise: Okay. And, Houston, stand by for a mark on another picture.

009:26:24 Brand: Rog. Standing by.

009:26:33 Haise: 3, 2, 1...

009:26:36 Haise: Mark it.

Figure AS13-80-8594 and SkySafari depiction

The next image is marked by Haise’s timer.

009:46:26 Haise: Yeah. I guess so. In a minute, you're going to hear my kitchen timer ding, and that also says the Earth is there.

009:46:39 Brand: Okay. [Long pause.]

009:46:57 Haise: Okay. Stand by, Vance, for our countdown. [Pause.]

009:47:09 Lovell: 3, 2, 1...

009:47:12 Lovell: Mark.

Figure has the details.

Figure AS13-80-8595 and SkySafari depiction

Figure shows number 7, with this record in the transcript as capcom remind them it’s almost time.

010:08:02 Brand: The Earth's coming up in the window again in 1 to 2 minutes.

010:08:08 Swigert: He's got it. You're right again. [Long pause.]

010:08:24 Swigert: Okay, stand by for a mark here.

010:08:26 Brand: Rog. [Long pause.]

010:08:38 Swigert: Okay, ready? 3, 2, 1...

010:08:40 Swigert: Mark.

Figure AS13-80-8596 and SkySafari depiction

Figure shows the next one:

010:29:56 Brand: Okay, Earth should be coming into view.

010:30:01 Haise: Okay. I got it. [Long pause.]

010:30:56 Swigert: Okay. Stand by, Vance. 3, 2, 1...

010:31:01 Swigert: Mark.

Figure AS13-80-8597 and SkySafari depiction

As is evident from the photos, Earth is gradually shrinking with the increasing distance, and Capcom asks them about the view:

010:31:14 Brand: Earth starting to look pretty small now?

010:31:23 Swigert: Well, looking at here, Vance, it's hard to be convinced it's even the Earth. All we see is water and clouds. [Pause.]

010:31:36 Brand: Well, I guess that's what we want. We want pictures of weather, right, clouds.

010:31:43 Swigert: Yeah, about half of it's covered with clouds.

Which indeed it is.

20 minutes later we have a reminder to take the next photograph.

010:51:33 Brand: Apollo 13, Houston.

010:51:37 Swigert: Go ahead, Vance.

010:51:40 Brand: Time to look out your window for us again.

010:51:46 Swigert: Lo and behold.

010:52:58 Swigert: Okay. It's 3, 2, 1...

010:53:01 Swigert: Mark.

Figure has the details.

Figure AS13-80-8598 and SkySafari depiction

The penultimate image is AS13-80-8599, shown in figure and alerted to the crew by capcom.

011:13:56 MCC: You should have the Earth coming into view here shortly.

011:14:02 Swigert: Okay. [Pause.]

011:14:12 Haise: We got a new CapCom now. [Long pause.]

011:14:29 Brand: No, I changed my voice. [Long pause.]

011:14:58 Haise: 3, 2, 1...

011:15:01 Haise: Mark.

Figure AS13-80-8599 and SkySafari depiction

After this last image, we have some discussion about what they’re looking at:

011:16:59 Haise: I guess the world really does turn. I can see some of my landmasses now. It must be Australia down near the bottom and I guess we haven't really figured out what's over the - to the left. It must be some part of Asia. China, probably.

011:17:19 Brand: Hey, maybe the fact that you verified that the Earth really turns, we can call this Haise's Theory, huh? [Pause.]

011:17:32 Haise: Very good, Vance. Very good.

011:17:36 Lovell: It's looking good for you, Vance.

011:17:39 Brand: No, seriously. Very interesting, we can see on the map now that you're between Guam and Hawaii and a little bit north, and you're almost out 60,000 miles [110,000 km].

As always, the view is completely accurate.

While the original plan was to take 10 images, the crew are requested to take one more for luck, and the moment is recorded as follows:

011:35:34 Brand: Okay, Jack, this is the last time for the Earth coming into view in about 1 to 2 minutes.

011:35:43 Swigert: Okay. I got my photographer looking out there.

011:35:47 Brand: Okay. [Long pause.]

011:35:59 Brand: 13, Houston. I just corrected. Actually, the Earth will come into view more times. It's just that we're [garbled] to the photography. Over.

011:36:12 Swigert: Okay.

Comm break.

011:37:17 Haise: 3, 2, 1...

011:37:20 Haise: Mark.

Figure shows this final photograph, and now that we’re at the end of the sequence it’s worth doing a full analysis, which is shown in figure

Figure AS13-80-8600

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

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. SkySafari 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 As for whether ESSA's timings can confirm the time given by the Apollo mission and SkySafari, 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:

The rotational movement over the sequence is undeniable.

There is a considerable time lapse between these images ant the next photographs of Earth, which is hardly surprising given that other events in the mission preoccupy them somewhat. The TV broadcast on the 13th doesn’t show Earth, and it’s day 4, the 14th, before we next see Earth photographs.