by alter-ego » Tue Sep 08, 2015 3:56 am
Nitpicker wrote:
...
Note that Debus has a diameter of about 20 km and the distance along the lunar surface, from the bottom of the frame to the horizon is about 250 km.
I agree with the craters.
The APOD primarily shows craters that are members of Pasteur (U, T) and Debus (U is the lower right crater, or the one connected to it on very lower-right corner). Mostly being smaller craters and greatly foreshortened, identification is difficult. I found Borman's B&W image (16:38:45) was the best for crater identification. The elevation map below shows the entire region with Apollo 8's location and image FoV for Borman's shot. The APOD image was taken about 1 minute later (~90km change in orbital position) and 3 common craters can be picked out.
[attachment=1]Apollo 8_Borman B&W Earthrise_163845 UT.JPG[/attachment]
[attachment=0]Borman Earthrise - Apollo 8.JPG[/attachment]
Regarding the horizon distances, I believe the mountain range between Pasteur and Ganskiy limits the bulk of "horizon" distance for both images, Borman's and the APOD. From Borman's location, the horizon distance ~560km. From the APOD's bottom edge, the horizon distance more likely ranges between 120km to 200km. I don't think it's possible to have the lower-elevation craters (e.g. Ganskiy) in either image, but there may be a few of the longer-range mountains peaking through. So roughly speaking, I estimate the horizon is at longitudes 97°E to 100°E.
I don't know if it's been stated earlier, but it's worth mentioning the terminator is at 30°E.
- Attachments
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![Borman Earthrise - Apollo 8.JPG (73.65 KiB) Viewed 3188 times Earthrise - 16:38:45 UT](./download/file.php?id=19710&t=1&sid=658a810f9a21434a8909d1c62a616dc8)
- Earthrise - 16:38:45 UT
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![Apollo 8_Borman B&W Earthrise_163845 UT.JPG (130.35 KiB) Viewed 3188 times Elevation Map showing FoV for Borman's Earthrise image and craters identified.](./download/file.php?id=19709&t=1&sid=658a810f9a21434a8909d1c62a616dc8)
- Elevation Map showing FoV for Borman's Earthrise image and craters identified.
[quote="Nitpicker"]
...
Note that Debus has a diameter of about 20 km and the distance along the lunar surface, from the bottom of the frame to the horizon is about 250 km.[/quote]
I agree with the craters.
The APOD primarily shows craters that are members of Pasteur (U, T) and Debus (U is the lower right crater, or the one connected to it on very lower-right corner). Mostly being smaller craters and greatly foreshortened, identification is difficult. I found Borman's B&W image (16:38:45) was the best for crater identification. The elevation map below shows the entire region with Apollo 8's location and image FoV for Borman's shot. The APOD image was taken about 1 minute later (~90km change in orbital position) and 3 common craters can be picked out.
[float=left][size=80][attachment=1]Apollo 8_Borman B&W Earthrise_163845 UT.JPG[/attachment][/size][/float][float=right][size=80][attachment=0]Borman Earthrise - Apollo 8.JPG[/attachment][/size][/float]
[hr][/hr]
Regarding the horizon distances, I believe the mountain range between Pasteur and Ganskiy limits the bulk of "horizon" distance for both images, Borman's and the APOD. From Borman's location, the horizon distance ~560km. From the APOD's bottom edge, the horizon distance more likely ranges between 120km to 200km. I don't think it's possible to have the lower-elevation craters (e.g. Ganskiy) in either image, but there may be a few of the longer-range mountains peaking through. So roughly speaking, I estimate the horizon is at longitudes 97°E to 100°E.
I don't know if it's been stated earlier, but it's worth mentioning the terminator is at 30°E.