The photograph was taken about 5 hours and 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. 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 1972 Tamil Nadu cyclone can be seen in the bottom left 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.
The photograph's official NASA designation is AS17-148-22727. NASA photograph AS17-148-22726, taken just before and nearly identical to 22727, is also used as a full-Earth image. The widely published versions are cropped and chromatically adjusted from the original photographs.
The photographer used a 70-millimeter Hasselblad camera with an 80-millimeter Zeiss lens. NASA credits the image to the entire Apollo 17 crew—Eugene Cernan, Ronald Evans and Harrison Schmitt—all of whom took photographs during the mission with the on-board Hasselblad, although evidence examined after the mission suggests that Schmitt was the photographer.
All Apollo flights were heavily scheduled down to the minute. At the time this photo was taken, none of the astronauts was scheduled to do so. Thus this photo was taken quickly in a stolen moment. The astronaut who took the picture was weightless, and the continents were hard to see, and he took the photo quickly, which explains why he held the camera upside down compared to the north up orientation of all maps. If every photo on this roll of film is printed, and all of the photos on the roll of film are oriented the same way, then when viewed in sequence, to put feet down and heads up, this photo will have the south pole up, breaking the map convention.
Apollo 17 was the last crewed lunar mission. No human since has been far enough from Earth to photograph a whole-Earth image such as The Blue Marble, but whole-Earth images have been taken by many uncrewed spacecraft missions.
The Blue Marble was not the first clear image taken of an illuminated face of Earth, since similar shots from the ATS-3 satellite had already been made as early as 1967. The Apollo 17 image, however, released during a surge in environmental activism during the 1970s, became a symbol of the environmental movement, as a depiction of Earth's frailty, vulnerability, and isolation amid the vast expanse of space. NASA archivist Mike Gentry has speculated that The Blue Marble is among the most widely distributed images in history.
source: wikipedia
