The Blue Marble is a photograph of Earth taken on December 7, 1972, by one of the astronauts aboard the Apollo 17 spacecraft on its way to the Moon. Viewed from around 29,400 kilometers (18,300 mi; 15,900 nmi) from Earth's surface, a cropped, rotated, and processed version has become one of the most reproduced images in history. In the original NASA image, named AS17-148-22727 and centered at about 26°19′49″S 37°25′13″E with the South Pole facing upwards, The Blue Marble shows Earth from the Mediterranean Sea to Antarctica. This was the first time the Apollo trajectory and seasonal timing made it possible to photograph the south polar ice cap, despite the Southern Hemisphere being heavily covered in clouds. In addition to the Arabian Peninsula and Madagascar, almost the entire coastline of Africa and most of the Indian Ocean are clearly visible, a cyclone in the Indian Ocean is also visible, the South Asian mainland and Australia are on the eastern limb, and the eastern part of South America lies on the western limb. The Blue Marble was preceded by two photos with the same perspective, which were taken immediately prior. NASA has also applied the name to a 2012 series of images which cover the entire globe at relatively high resolution. These were created after a search of satellite pictures taken over time found as many cloudless photographs as possible for use in the final images. NASA has verified that the 2012 "blue marble" images are composites, made from multiple images taken from low Earth orbit, an altitude whose narrow field of view does not allow of photographing the entire planet at once. Likewise, these images do not fit together properly and, because of lighting, weather and cloud interference, it is impossible to collect cohesive or fully clear images of the entire Earth simultaneously.
Background
The Blue Marble was not the first clear color image taken of an illuminated face of Earth, since such images by satellites had already been made and released as early as 1967. Before the Blue Marble, a picture of the fully illuminated Earth by the ATS-3 satellite was used in 1968 by Stewart Brand for his Whole Earth Catalog, after campaigning since 1966 to have NASA release a then-rumored satellite image of the entire Earth as seen from space. He got inspired during an LSD trip, seeing a "psychedelic illusion" of the Earth's curvature, convincing him that a picture of the entire planet would change how humans related to it. He sold and distributed buttons for 25 cents each that asked: "Why haven't we seen a photograph of the whole Earth yet?" During this campaign, Brand met Buckminster Fuller, who offered to help Brand with his project. Several of the pins made their way to NASA employees.
In the same year the popular photograph Earthrise was taken by William Anders of Apollo 8 and eventually in 1969 the crew of Apollo 10 took a photo of the almost completely illuminated Earth, which was then used for the first version of the Earth Flag, before being replaced by the Blue Marble photo.
Circumstance
The photograph was taken on December 7, 1972, aboard the Apollo 17 command module with callsign America.
Apollo 17 was the first mission that had the opportunity to photograph most of the Earth face completely lit in daylight, an opportunity prepared for and tightly observed and vividly described by the crew.The astronauts had the Earth's South Pole facing upwards and the Sun above them (in spatial navigation terms, to their zenith) when they took the image. To the astronauts, the Earth had the appearance and size of a glass marble.
At that time, Africa was in noon daylight and with the December solstice approaching, Antarctica was also illuminated. The picture has a 50% (26-50%) cloud cover, and shows many weather systems, featuring a Shapyro–Keyser cyclone near to the center of the image. Cyclone Sixteen (16B) can be seen in the upper right of the image. This storm had brought flooding and high winds to the Indian state of Tamil Nadu on December 5, two days before the photograph was taken. According to the photograph description by NASA it was taken at 05:39 a.m EST (10:39 UTC), 5 hours 6 minutes after launch of the Apollo 17 mission, and about 1 hour 54 minutes after the spacecraft left its parking orbit around Earth to begin its trajectory to the Moon. Alternatively, Eric Hartwell has identified it as having been taken slightly earlier at 5 hours 3 minutes, when one crew member states having changed the f-number, presumably between AS17-148-22725, the first of the sequence of photos, and the following less exposed images like The Blue Marble.
Schmitt used a 70-millimeter Hasselblad 500 EL camera with an 80-millimeter Zeiss planar lens; the film stock was Kodak SO-368 Ektachrome film, the lens was set at f/2.8 and the shutter speed was 1/250 of a second.
Release
The photograph's official NASA designation is AS17-148-22727. It is the third of a sequence of shots which were taken just before and are nearly identical, NASA photograph AS17-148-22725 and AS17-148-22726, the second also having been used as a full-Earth image. The widely published versions are cropped, rotated with south pointing up relative to the capsule, and chromatically adjusted from the original photographs.
Authorship NASA generally credits images to the whole crew of a mission. All crew members, Gene Cernan, Ronald Evans and Harrison Schmitt, took photographs during the mission with the onboard Hasselblad. They have largely avoided definitively answering the question of the photographer's identity by each member claiming to have taken it. However, interviews and evidence examined by Eric Hartwell after the mission suggest that Schmitt was the photographer. For example, in 2013, Schmitt gave a phone interview for the website The Phoblographer in which he explained some of the camera settings, and recalled that the reason the photograph was taken stemmed from his hobby as an amateur meteorologist, with weather prediction being a personal mission goal; Schmitt did not anticipate the image's popular acclaim.
Processing
The original camera film was rescanned in 2007 by the Arizona State University (ASU) for their Apollo Image Archive, producing an extremely high resolution raw version.
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