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Author
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Topic: Earth photos taken on the lunar surface
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LM-12
Member Posts: 3324
From: Ontario, Canada
Registered: Oct 2010
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posted 08-18-2014 09:58 PM
  
Apollo 11 frame 5924 and Apollo 17 frame 20463 are two Earth photos taken during EVA activities. You can tell by looking at the Earth terminator that the two landing sites are at different latitudes.
I do not see the Reseau numbers on some of the Earth photos that Gene Cernan took. Perhaps it was an awkward angle, so I suspect that Cernan may have held his camera upside down or sideways to take those shots, including: - frames 20957 to 20961 at Station 2
- frames 20465 and 20466 at the flag
- frame 20471 at the rover
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Headshot
Member Posts: 891
From: Vancouver, WA, USA
Registered: Feb 2012
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posted 08-19-2014 06:57 AM
I believe that the latitude of a lunar landing site can be roughly determined by the altitude of the Earth above the lunar horizon, e.g. the Earth would be on the horizon at the Moon's poles and be almost overhead when viewed from the lunar equator.I am not certain that the Earth's terminator has any bearing on the latitude of a lunar landing site, although it might be used to determine the difference in longitude between two different landing site. Someone help us out with this. |
schnappsicle
Member Posts: 396
From: Houston, TX, USA
Registered: Jan 2012
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posted 08-19-2014 07:16 AM
You are correct on both counts. The earth goes through phases just like the moon does when viewed from earth, but unlike the moon, the earth stays roughly in the same spot in lunar sky at all times.
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LM-12
Member Posts: 3324
From: Ontario, Canada
Registered: Oct 2010
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posted 08-19-2014 08:33 AM
Using Apollo 17 frame 20961 as an example:It would seem to me that (hypothetically) if someone was standing on the lunar equator when Cernan took that photo, they would see a horizontal Earth terminator. And someone standing on the lunar north or south pole would see a vertical Earth terminator. Is that correct? |
One Big Monkey
Member Posts: 171
From: West Yorkshire, UK
Registered: Jul 2012
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posted 08-19-2014 09:28 AM
This superb analysis takes the idea a step further! |
Headshot
Member Posts: 891
From: Vancouver, WA, USA
Registered: Feb 2012
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posted 08-19-2014 09:45 AM
Yes LM-12, your reasoning is correct also. The angle of the Earth's terminator would vary by latitude as well.It is best to measure the angle of the terminator during half-Earth, when the terminator is a straight line. Despite what that excellent video shows, when the Earth is gibbous there is some subjectivity to determining the terminator angle. |
Glint
Member Posts: 1044
From: New Windsor, Maryland USA
Registered: Jan 2004
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posted 08-19-2014 01:30 PM
The angle of the terminator primarily varies by season. The seasons are caused by the earth's axial tilt.
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LM-12
Member Posts: 3324
From: Ontario, Canada
Registered: Oct 2010
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posted 08-19-2014 02:47 PM
Frame 9189 is a LM and Earth view from the lunar surface on Apollo 14.None of the Apollo 15 and Apollo 16 Hasselblad photos taken on the lunar surface seem to show the Earth. That is a surprise. Can you find any? |
LM-12
Member Posts: 3324
From: Ontario, Canada
Registered: Oct 2010
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posted 08-21-2014 12:50 PM
I take it from the "superb" Earthrise video that One Big Monkey posted above that (1) the angle of the Earth's axis relative to the lunar horizon changes with latitude and can be used to determine lunar latitude, and (2) the elevation of the Earth above the lunar horizon changes with longitude and can be used to determine lunar longitude.So, if one can do all the calculations, the (approximate) location where an Earth photo like 20961 was taken can be determined from the photo alone? Amazing. |
LM-12
Member Posts: 3324
From: Ontario, Canada
Registered: Oct 2010
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posted 09-01-2014 08:04 AM
The view of Earth in the Apollo 11 emblem is wrong for where they landed. And when they landed also, I believe. |
moorouge
Member Posts: 2458
From: U.K.
Registered: Jul 2009
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posted 09-01-2014 10:59 AM
quote:
Originally posted by LM-12:
The view of Earth in the Apollo 11 emblem is wrong for where they landed. And when they landed also, I believe.
It also needs to be rotated 90 degrees. I believe Mike Collins has owned up to his astronomical error. |
LM-12
Member Posts: 3324
From: Ontario, Canada
Registered: Oct 2010
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posted 09-01-2014 05:58 PM
"... wrong for where they landed" is the 90 degree error.An Earth view like frame 5924 should be on the emblem: upper half in sunlight with north pole at right. When Apollo 11 landed at 4:17:39 p.m. EDT, the eastern part of North America should have been visible in the sunlit half. |
Robert Pearlman
Editor Posts: 43576
From: Houston, TX
Registered: Nov 1999
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posted 09-01-2014 06:03 PM
quote:
Originally posted by moorouge:
I believe Mike Collins has owned up to his astronomical error.
From "Carrying the Fire" by Collins: I added a small earth in the background and drew the sunshine coming from the wrong direction... |
LM-12
Member Posts: 3324
From: Ontario, Canada
Registered: Oct 2010
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posted 09-01-2014 06:37 PM
Where would you have to be on the moon and when would you have to be on the moon to see the Earth view in the Apollo 11 patch?My guess is in the northwest quadrant of the moon near the lunar north pole, on a waning crescent moon. |
LM-12
Member Posts: 3324
From: Ontario, Canada
Registered: Oct 2010
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posted 09-03-2014 10:23 AM
The sunlight direction in the Apollo 14 emblem also looks wrong. In the Apollo 8 emblem, the moon is sunlit from the right as seen from the Earth. That seems right for when Apollo 8 flew.An interesting change in the Apollo 8 emblem would be to switch the positions of the Earth and the moon, and have the moon in the foreground. Then the names of the three crewmembers would be in orbit at the moon. |
LM-12
Member Posts: 3324
From: Ontario, Canada
Registered: Oct 2010
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posted 10-24-2014 12:50 PM
Was it ever determined who took Apollo 11 frames 5923 and 5924?In frame 5924, there is a bright object seen at right center. Is that a star or perhaps a planet, or is it just a flaw on the film? |
LM-12
Member Posts: 3324
From: Ontario, Canada
Registered: Oct 2010
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posted 03-12-2015 02:55 PM
From the Apollo 12 mission transcripts at the end of EVA-2, when Al Bean was back inside the LM and Pete Conrad was still on the lunar surface: CDR-EVA: Did you ever get the picture of the LM and Earth?LMP-LM: No. CDR-EVA: Oh, that's a shame. LMP-LM: I know it. CDR-EVA: Hi Earth; I can see us. It's up over the LM now. It's the first time I've had a chance to look. You're about a quarter Earth. |
LM-12
Member Posts: 3324
From: Ontario, Canada
Registered: Oct 2010
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posted 04-30-2016 12:29 AM
I added a small earth in the background and drew the sunshine coming from the wrong direction... Has there ever been an illustration showing a "corrected" version of the Apollo 11 emblem? That is, a design that replaces the wrong view of Earth in the original emblem with a correct view of Earth as seen in photo AS11-44-6551 for example.
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DFBrunswick
Member Posts: 40
From: California, USA
Registered: May 2015
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posted 06-11-2017 02:04 AM
During the Apollo missions, was Earth always visible from the lunar surface? I presume not because there were no photographs of Earth that I know from the lunar surface during the Apollo 11 and 12 missions. In fact the only photographs of Earth from the lunar surface that I know of were from the Apollo 17 mission. Did any of the other Apollo missions (Apollos 11 - 16) photograph Earth from the surface of the moon? Editor's note: Threads merged. |
Jurg Bolli
Member Posts: 994
From: Albuquerque, NM
Registered: Nov 2000
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posted 06-11-2017 06:42 AM
The Earth is always visible from the near side of the moon in the same place in the sky, the only thing that changes are the phase that the Earth is in. |
Headshot
Member Posts: 891
From: Vancouver, WA, USA
Registered: Feb 2012
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posted 06-11-2017 03:04 PM
The Earth does not stay precisely in the same spot in the lunar sky. Due to lunar libration, the Earth wanders, albiet slightly, to and fro along a short line during a lunar orbit. |
One Big Monkey
Member Posts: 171
From: West Yorkshire, UK
Registered: Jul 2012
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posted 06-12-2017 12:31 PM
quote:
Originally posted by DFBrunswick:
Did any of the other Apollo missions (Apollos 11 - 16) photograph Earth from the surface of the moon?
The Earth was photographed from the surface by Apollo 11 and Apollo 14 and was also broadcast on TV during Apollo 16. |
moorouge
Member Posts: 2458
From: U.K.
Registered: Jul 2009
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posted 07-04-2017 05:12 AM
LM-12 - can you please email me (address on profile) as I have something that I'd like your opinion on regarding earth photos taken on the Moon.
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