The Blue Marble

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The Blue Marble is a famous photograph of the Earth taken on 7 December 1972 by the crew of the Apollo 17 spacecraft at a distance of about 45,000 kilometers or about 28,000 miles.[1] It is one of the most widely distributed photographic images in existence. The image is one of the few to show a fully lit Earth, as the astronauts had the Sun behind them when they took the image. To the astronauts, Earth had the appearance of a child's glass marble (hence the name).

Original caption: "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 Madagascar. The Asian mainland is on the horizon toward the northeast."

[edit] History

The photograph was taken on December 7, 1972 at about 5:39 a.m. EST (10:39 UTC), about 5 hours 6 minutes after launch [2], and about 1 hour 48 minutes after the spacecraft left parking orbit around the Earth to begin its trajectory to the Moon. The time of Apollo 17's launch, 12:33 a.m. EST, meant that Africa was in daylight during the early hours of the spacecraft's flight. With the December solstice approaching, Antarctica was also illuminated.

The photograph's official name is AS17-148-22727. (The photograph AS17-148-22726, taken just before and nearly identical to 22727, is also used as a full-Earth image.) The photographer used a 70-millimeter Hasselblad camera with an 80-millimeter lens. NASA officially credits the image to the entire Apollo 17 crew — Eugene Cernan, Ronald Evans and Jack Schmitt — all of whom took photographic images during the mission with the on-board Hasselblad. Schmitt later claimed that he personally took the famous image, but the identity of the photographer is unverifiable.

Apollo 17 was the last manned lunar mission. No humans since have been at a range where taking a "whole-Earth" photograph such as "The Blue Marble" would be possible.

"The Blue Marble" was the first clear image of an illuminated face of Earth. Released during a surge in environmental activism during the 1970s, the image was seen by many as a depiction of Earth's frailty, vulnerability, and isolation amid the expanse of space. NASA archivist Mike Gentry has speculated that "The Blue Marble" is the most widely distributed image in human history.

Subsequent similar images of Earth (including composites at much higher resolution) have also been termed "blue marble" images, and the phrase "blue marble" (as well as the picture itself) is used frequently by environmental activism organizations or companies attempting to promote an environmentally conscious image. There has also been a children's television program called Big Blue Marble.

"Blue Marble" composite images generated by NASA in 2001 (left) and 2002 (right).

The picture was originally taken upside down from the usual view of North at the top, but was rotated before it was distributed. [3] This presumed "upside down" picture is one of the arguments for the reversed map theory.

[edit] See also

• Stewart Brand
• Whole Earth Catalog
• Pale Blue Dot
• Earthrise

[edit] External links

[edit] 1972 photo

• The one, the only, photograph of Earth a short list of places in which the image has been used.
• Apollo Image Atlas Photos from magazine NN of the 70mm Hasselblad camera used on Apollo 17 (includes the Blue Marble photo and others quite similar to it)

[edit] 21st century NASA composite images

• Blue Marble (2002)
  • Extremely high resolution version of the above
  • Blue Marble Mapserver Web interface for viewing small sections of the above
• Blue Marble: Next Generation (2005; one picture per month)
  • Blue Marble Navigator Web interface for viewing local sections of the above, incl. links to other such interfaces, download sites etc.
  • Blue Marble: Next Generation in NASA World Wind