The Blue Marble

On December 7, 1972, an astronaut on the Apollo 17 spacecraft, en route to the Moon, captured a photograph of Earth. Taken from roughly 29,400 kilometers above the planet’s surface, the image—after being cropped, rotated, and processed—has become one of the most widely reproduced pictures ever made. The original NASA image, cataloged as AS17-148-22727, shows Earth from the Mediterranean Sea down to Antarctica, with the South Pole oriented toward the top. This was the first time the Apollo mission’s trajectory and seasonal timing allowed the south polar ice cap to be photographed, even though the Southern Hemisphere was heavily clouded.

Visible in the frame are the Arabian Peninsula, Madagascar, nearly the entire African coastline, most of the Indian Ocean, a cyclone in that ocean, the South Asian mainland and Australia along the eastern limb, and the eastern part of South America on the western limb. Two nearly identical photos were taken just before this one. NASA later applied the name “Blue Marble” to a 2012 series of high-resolution global images. Those were composites, assembled from many satellite pictures taken over time, chosen for their lack of cloud cover.

Background

Because they were captured from low Earth orbit—where the narrow field of view cannot show the whole planet at once—the images do not align perfectly, and lighting, weather, and cloud interference make it impossible to collect a cohesive, fully clear picture of the entire Earth simultaneously. The Blue Marble was not the first clear color image of Earth’s illuminated face; satellites had produced such pictures as early as 1967. Before it, a 1968 image from the ATS-3 satellite was used by Stewart Brand for his Whole Earth Catalog. Brand had campaigned since 1966 for NASA to release a rumored satellite photograph of the whole Earth, inspired during an LSD trip by a “psychedelic illusion” of the planet’s curvature.

He believed such a picture would change humanity’s relationship with Earth. He sold and distributed buttons for 25 cents each that read: “Why haven’t we seen a photograph of the whole Earth yet?” During this campaign, he met Buckminster Fuller, who offered assistance, and several pins reached NASA employees. In 1969, the Apollo 10 crew took a photo of an almost fully illuminated Earth, which was used for the first version of the Earth Flag, before the Blue Marble replaced it. That same year, the famous Earthrise photograph had been taken by William Anders of Apollo 8.

Circumstance

The photograph was taken on December 7, 1972, aboard the Apollo 17 command module, callsign America. Apollo 17 was the first mission with the opportunity to photograph most of Earth’s face fully lit in daylight—an opportunity the crew had prepared for, closely observed, and vividly described. The astronauts oriented the image with the South Pole upward and the Sun above them (to their zenith in spatial navigation terms).

To them, Earth looked like a glass marble in size and appearance. At the time, Africa was in noon daylight, and with the December solstice approaching, Antarctica was also illuminated. The picture shows about 50% cloud cover (26–50%), including many weather systems. A Shapiro–Keyser cyclone appears near the image’s center, and Cyclone Sixteen (16B) is visible in the upper right.

That storm had caused flooding and high winds in the Indian state of Tamil Nadu on December 5, two days before the photo was taken. According to NASA’s description, the photograph was taken at 5:39 a.m. EST (10:39 UTC), 5 hours and 6 minutes after the Apollo 17 launch, and about 1 hour and 54 minutes after the spacecraft left its parking orbit around Earth to head for the Moon. Alternatively, Eric Hartwell identified it as having been taken slightly earlier, at 5 hours and 3 minutes, when a crew member mentioned changing the f-number between the first photo in the sequence (AS17-148-22725) and the later, less exposed images like the Blue Marble.

Release

Astronaut Schmitt used a 70-millimeter Hasselblad 500 EL camera with an 80-millimeter Zeiss planar lens, loaded with Kodak SO-368 Ektachrome film. The lens was set at f/5.6, and the shutter speed was 1/250 of a second. The photograph’s official NASA designation is AS17-148-22727. It is the third in a sequence of nearly identical shots taken just before it; the first two are AS17-148-22725 and AS17-148-22726, with the second also having been used as a full-Earth image.