Apollo 17: The Blue Marble
"The Blue Marble" is one of the most widely distributed photographic images
in existence, but NASA says the identity of the photographer is unverifiable.
I decided to take that as a personal challenge.
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Original NASA Caption,
Saturday December 23, 1972:
View of the Earth as seen by the Apollo 17 crew traveling toward the
moon. This translunar coast photograph extends from the
Mediterranean Sea area to the Antarctica south polar ice cap. This is
the first time the Apollo trajectory made it possible to photograph the
south polar ice cap. Note the heavy cloud cover in the southern
hemisphere. Almost the entire coastline of Africa is clearly visible.
The Arabian Peninsula can be seen at the northeastern edge of Africa.
The large island off the coast of Africa is the Malagasy Republic. The
Asian mainland is on the horizon toward the northeast.
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Earth is said to have the appearance of a child's marble in the photo;
that is the Earth has the same aspect at this distance as a child's marble
at about arm's length.
NASA officially credits the image to the entire
Apollo 17 crew — Eugene Cernan, Ronald Evans and Jack Schmitt — all of whom
took photographic images with the on-board Hasselblad. Schmitt later claimed that he personally took the
famous image, but the identity of the photographer is unverifiable.
-- from Wikipedia entry for "The Blue Marble"
as of March 22, 2006 |
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By Eric Hartwell - Last
updated Wednesday April 25, 2007
When I started this project, I expected to prove that the "Blue Marble" photo was taken by
Jack Schmitt as commonly accepted. More than a year later, the answer is still
up in the air. I've established
almost everything else:
"Did you get any pictures of that?"
NASA released the photo on Saturday December 23, 1972, one of
eight photos in the second batch released. It
made the front page of most newspapers over the Christmas
weekend. Who gets the credit?
- Credit, Crew:
- The original NASA photo release gave credit to the
entire crew.
- No, Jack:
- A UPI wire story released on Saturday December 23, 1972
credited Schmitt, apparently based on the reporter's
interpretation of the ground-to-earth communications from
December 7.
-
- No, Crew:
- The UPI caption for the wire photo released on
Saturday December 23, 1972 credited the crew. The AP caption
and AP stories credited the crew.
- No, Crew:
- "The crew accept credit for that picture as a whole.
I've actually been to events where all three of them kind of
jokingly take credit for it. And we've never really been
able to quite pin down which one of the crewmen, Cernan,
Evans or Schmitt took the picture. ... No one at that time
in our photo lab had any idea I think of how long lasting it
would be..." -- Mike Gentry, NASA Media Resource Centre,
1999 [ref]
- No, Ron:
- Early in the mission, Astronaut Ron Evans made his most
notable photographic contribution; he took a picture that
will rank among the classics of the space program. As Apollo
sped toward the moon after blasting into its translunar
trajectory, he pointed his camera back toward home and
caught a stunning view of the earth, with the side visible
to the astronauts completely illuminated. --
Portfolio from Apollo -- Time Magazine -- Monday, January 8, 1973
- No, Gene:
- "I've actually been to events where all three of
them kind of jokingly take credit for it." -- Mike
Gentry, again
- No, Jack:
- "I've actually been to events where all three of
them kind of jokingly take credit for it." -- Mike
Gentry, again
Who's on First
 The Detailed Timeline shows that the
"Blue Marble" photo was taken between 5:00 and 5:08 after launch. The Apollo
spacecraft was facing back towards the Earth, and the astronauts were still in
their space suits.
The time of Apollo 17's launch, 12:33 a.m. EST, meant that Africa was in daylight,
and with the December solstice approaching,
Antarctica was also illuminated.
 The photograph was taken at a distance of about 45,000 kilometers, about 1 hour 48 minutes after the spacecraft left Earth orbit on
its way to the Moon, and about 5 hours 6 minutes after launch. The
spacecraft's trajectory aligned it with the Earth and Sun, providing a view
of an almost completely full Earth.
Command Module Pilot (CMP) Ronald Evans was in the left-hand seat. After docking
with the Lunar Module (LM) and extracting it from the S-IVB, Evans initiated a
separation maneuver, then pitched the CSM/LM stack down so that the S-IVB was
clearly visible through the center, hatch window.
Commander (CDR) Eugene Cernan was in the center seat. After the Command
and Service Module (CSM) docked with the LM, Cernan went down into the short
tunnel leading to the lander, opened the hatch cover, and verified the
latches holding the two spacecraft together. He connected electrical umbilical
cables, reinstalled the hatch, then returned to his seat to observe the S-IVB.
Lunar Module Pilot (LMP) Jack Schmitt was in the right-hand seat,
observing, photographing, then monitoring the LM. During this part of the flight
Schmitt managed communications and the flight plan checklist and updates.
The astronauts were waiting to watch the S-IVB
as it fired its engines to send it into a controlled crash on the Moon.
"We'd like to confirm, from the crew of America, that the world is round."
 All three astronauts took photos during this period.
The spacecraft was facing back towards the Earth, pitched down so that the S-IVB
was clearly visible through the Command Module's hatch window.
I've determined the actual orientation of the S-IVB/LM relative to
the Earth by pasting together the
16 mm movie frames from the pitch maneuver.
Since the pitch maneuver was performed at a constant rate, it's possible to
measure the angles directly from the combined image. The center of the Earth was
70° down from the CSM / S-IVB/LM axis.
The Earth was visible through the side windows, 1 and 5, but probably blocked
by the LM through the other windows. This narrows the possibilities down to
Evans or Schmitt ... or, possibly Cernan. Oops.
After
separation and pitch down, Evans took some photos of the Earth. [004:47] "Okay. POWER's OFF. Hey, Jack.
Hand me the Hasselblad. I think we're bowing the right direction. Yes,
the Moon is there. The Earth is - that's
the Earth. ... The Earth just fills up window 5.
Okay, f infinity, about a 250th."
He then passed the camera to Cernan, who photographed the S-IVB: "Let's get a picture or two here yet, and we'll give you a GO....
[004:56] ... And for your reference, at frame 105 I started a few 250-millimeter
pictures of the S-IVB".
After they switched to the 80mm lens some
time between 5:00 and 5:03 GET, first photo was of the S-IVB (22724), and
the second was of the Earth (22725). The next three photos (22726-7-8) were the
"Blue Marble".
Murphy's law steps
in.
January 16, 2006:
there are critical disagreements between the PAO Mission Commentary Transcript
and the Technical Air-to-Ground Voice Transcription,
and the Onboard Voice Transcription is missing
the entire period from 1:27 to 35:30. I'm now pursuing the original transcript
and/or tapes. - Eric
-- PAO --
SC Okay, you have a GO. And for
your reference, it's frame 105, I started a few 250 millimeter
pictures of the S-IVB.
CC Roger, Gene.
-- TECHNICAL --
CDR Okay. You have a GO.
LMP And for your reference, at
frame 105 I started a few 250-millimeter pictures of the S-IVB.
CC Roger, Jack.
My theory
(and what it is, too)
There's a more detailed analysis in the
Overview section. I've prepared a separate Detailed Timeline
combining the flight plan, capsule communications transcript, and photos, and a
Geometry section discussing who and what was where, and the view from each
window. I've also collected information about the
Cameras and Photos, and posted a copy of
the
Image Catalog for the Apollo 17 photos
from Earth orbit to the moon.
Here's my reconstruction of the actual events:
March 22, 2006: I still believe Schmitt took the picture, but I still don't have a definitive transcript, so we
still don't know for sure who said what. Still working on it, still. - Eric
004:59 Cernan: "I know we're not the first to discover this - but
we'd like to confirm, from the crew of
America, that the world is round."
CapCom: "Roger. That's a good data point."
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#110 AS17-148-22717 |
#111 AS17-148-22718 |
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#112 AS17-148-22719 |
#113 AS17-148-22720 |
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#114 AS17-148-22721 |
#115 AS17-148-22722 |
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#116 AS17-148-22723 |
#117 AS17-148-22724 |
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#118 AS17-148-22725 |
#119 AS17-148-22726 |
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#120 AS17-148-22727
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#121 AS17-148-22728
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CapCom: "Have you gotten a good look at any of that
weather down there on the Antarctic?"
Cernan: "Well, Ron's at window number 1 - maybe he can tell you a little about it."
Evans: "You know, it's real funny there in Antarctica the - You can see the snow,
but there isn't any weather at all in it. All of the weather's around it in the
water."
Schmitt: "That's where the moisture is."
Schmitt?Evans? "I
don't know what to take a picture of."
- Both Evans and Schmitt are looking at the Earth through their side
windows. Schmitt takes a series of Earth photos (#110 AS17-148-22717 through
#115 AS17-148-22722) with varying exposures, using the
telephoto lens.
...
005:02: Cernan?Schmitt? "No, I'll change lens now."
-
They
change the lens from 250mm telephoto to 80mm normal in
preparation for the S-IVB burn. While changing the lens, they bump the
shutter causing the blank frame (#118, AS17-148-22724). Cernan takes the photo
of the S-IVB (#118, AS17-148-22724) through the hatch window.
Cernan?Evans? "Okay. Here Jack, can you see it good?"
Schmitt?Evans?Cernan?
"Check the lens[settings] now. I took an F-22 stop."
-
Cernan: "Okay. Here Jack, can you see it good?"
Schmitt: "Check the lens[settings] now. I took an F-22 stop."
- Cernan passes the camera to Schmitt
so he can photograph the whole Earth with the normal lens. Schmitt
takes the first picture (frame #119, AS17-148-22725) then remembers to
change
the f-stop to compensate for the brightness of the Earth. Schmitt then takes
three more photos, with slightly different aim because there's no viewfinder
and he wants to make sure to get the whole planet in the picture.
These photos are the famous "Blue Marble".
- Schmitt passes the camera back to Cernan for pictures of the S-IVB burn
through the hatch window. Schmitt reminds Cernan he changed the lens
setting.
- Cernan:
"Okay. Here Jack, can you see it good?"
Cernam: "Check the lens[settings] now. I took an F-22 stop."
- Cernan passes the camera to Schmitt
so he can photograph the whole Earth with the normal lens. Schmitt
takes the first picture (frame #119, AS17-148-22725) then Cernan reminds him
to change
the f-stop to compensate for the brightness of the Earth. Schmitt then takes
three more photos, with slightly different aim because there's no viewfinder
and he wants to make sure to get the whole planet in the picture.
These photos are the famous "Blue Marble".
Cernan: "There it goes, Bob."
Schmitt? "There it goes, finally."
- S-IVB evasive burn starts (no photo)
Schmitt? "It's going to be gone, I think, before we -"
Evans? "Houston, Magazine, November, November is
on about 123 right now."
- Cernan didn't get a photo of the S-IVB through the hatch window. He
passes the camera to Evans so he can take a parting shot through window 1,
but it's too late.
- Evans reports the
frame count.
[Note: Frame count is +-1 due to the analog
frame counter] .
Portfolio from Apollo
Time Magazine gave Evans credit for the photo in an article discussing the
mission's photography, published 3 weeks after landing:
Early in the mission, Astronaut Ron Evans made his most notable
photographic contribution; he took a picture that will rank among the
classics of the space program. As Apollo sped toward the moon after
blasting into its translunar trajectory, he pointed his camera back toward
home and caught a stunning view of the earth, with the side visible to the
astronauts completely illuminated. In crystal-clear detail it shows almost
the entire coastline of Africa and the offshore island republic of Malagasy,
the Arabian peninsula and an unusually thick cover of swirling clouds over
Antarctica and the surrounding region at the bottom of the world.
Portfolio from Apollo -- Time Magazine -- Monday, January 8, 1973
No source is given for this statement; while it may have been based on an
interview with the astronauts, there's no proof. As we shall see, according to
the geometry, the timeline, and the transcripts, it could have been either Evans
or Schmitt.
Testing the
Theory: Need Input. More Input.
Of course, this is speculation based on contradictory, circumstantial evidence. NASA's
policy is to credit photos to the entire crew unless there's only one person who
could have possibly taken it. The astronauts were very busy at the time the
picture was taken, observing the S-IVB and the Earth, and passing the camera
back and forth, so it could have been any of them.
There are a number of things we can do to refine or disprove this theory:
- Get a copy of the original
audio tape to verify the transcript, identify the speakers, and narrow down
the actual times
March update: Waiting on NASA archives
- See if there's movie footage
that can help narrow the timeline
March update: The 16mm film of the S-IVB firing doesn't add much. It
appears the camera was handheld, and after the burn, the camera was turned
on again for a few frames of the "Blue Marble".
- Try to run an accurate simulation of Apollo 17's TD&E using Orbiter to
establish the actual fields of view from windows 3 and 5.
March update: Orbiter is a serious simulator, and I'm still learning how
to use it.
- Ask Cernan and Schmitt to comment
- Ask other commanders and LM
pilots to comment
References
- Based on Wikipedia entry for "The Blue Marble"
as of March 22, 2006
- NASA Scientific Visualization Studio:
Apollo 17
30th Anniversary: Antarctica Zoom-out
- NASA
History Publications On-Line
- The Apollo Program -
NASA's NASA and Non-NASA Links About Apollo
- Apollo Image
Atlas ...
Apollo 17 Image Catalog
- Apollo Lunar Surface
Journal ...
Apollo 17 Lunar Surface Journal
- JSC History Portal:
History Collection,
History
Index, Archive Index
- The Gateway to Astronaut
Photography of Earth - NASA Earth Sciences
- Alexandra de Blas interviewing Mike Gentry, NASA
Media Resource Centre, Johnson Space Centre , Houston, Texas,
World Environment Day: Spaceship Earth, Earthbeat (Australian
Broadcasting Corporation - Radio National), Saturday, June 5, 1999
Revision History
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