A little more than three years after Neil Armstrong took mankind’s first steps on the moon, Apollo 17 astronauts left the last footprints on the lunar surface in December of 1972. Described by NASA as “the last, longest, and most successful” of the manned lunar landing missions, Apollo 17 yielded significant scientific discoveries and produced one of the most famous images in history of planet Earth.

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The mission began on December 7, 1972 when, at 33 minutes past midnight, the engines of a Saturn V rocket erupted and bathed Florida’s Cape Canaveral in an orange glow. As night turned to day, the fireball blinded spectators who came to see Apollo 17 roar skyward.

Within minutes, the plume of flame faded to a speckle among the stars as the Apollo program launched its final mission to the moon. The Apollo 17 crew included commander Eugene Cernan, command module pilot Ronald Evans and lunar module pilot Harrison “Jack” Schmitt—the first astronaut originally trained as a scientist to soar into space.

A geologist with a doctorate from Harvard University, Schmitt had been among six scientists selected from a pool of 1,400 applicants to join the astronaut corps in 1965. He had been assigned to the crew of Apollo 18, but when budget cuts led NASA to cancel that mission along with Apollo 19 and 20, agency administrators assigned him to replace astronaut Joe Engle on the last lunar flight.

Four days after Apollo 17’s launch, Evans orbited the moon as Schmitt and Cernan landed the lunar module Challenger in the narrow Taurus-Littrow valley, which is deeper than the Grand Canyon and marked the easternmost landing site of any Apollo mission. Schmitt and Cernan—a veteran astronaut who had flown aboard Gemini 9 and Apollo 10—spent seven-hour stints on three consecutive days exploring the surrounding craters, boulders and mountains. Below a half-Earth hanging in the black sky, they assembled a science station to relay data, took gravity measurements, chipped fragments off ancient boulders and collected subsurface core samples.

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The astronauts drove their battery-powered lunar rover more than 20 miles across the moon’s surface—despite a fender bender. When a hammer Cernan accidentally dropped knocked a wheel fender off the rover, the astronauts crafted a replacement by duct taping four stiff maps together and attaching the makeshift flap to the fender with two clamps. The Auto Body Association of America bestowed lifetime memberships upon the pair for their makeshift fix.

During their second moonwalk, the astronauts were exploring the rim of Shorty Crater when Schmitt exclaimed, “There is orange soil!” Cernan confirmed the colorful find amid the gray dust: “He’s not going out of his wits. It really is.”

According to NASA Chief Historian Brian Odom, the samples collected by the astronauts from the crater rim were found to be composed of volcanic glass formed during a volcanic explosion. “The samples tell us that volcanic material originated from the moon and not from a meteorite impact,” he says. The discovery is considered one of the most important of the entire Apollo program.

Before concluding the mission’s third and final moonwalk, the astronauts offered epitaphs for the Apollo program. “This valley of history has seen mankind complete its first evolutionary steps into the universe,” said Schmitt, who later represented New Mexico in the U.S. Senate. “I think no more significant contribution has Apollo made to history.”

“America’s challenge of today has forged man’s destiny of tomorrow,” Cernan said. “And, as we leave the moon at Taurus-Littrow, we leave as we came and, God willing, as we shall return, with peace and hope for all mankind.” Before taking humanity’s last steps on the moon, the commander knelt and scratched his daughter’s initials in the lunar dust. Challenger blasted off from the moon and left behind a plaque that reads: “Here man completed his first explorations of the moon.”

Cernan and Schmitt spent 22 hours and 4 minutes outside the lunar module, surpassing the entire time that Apollo 11 spent at Tranquility Base. Public interest, however, could not compare to the historic moonwalk by Armstrong and Buzz Aldrin.

After five previous lunar landings, familiarity bred apathy among the American public. While fledgling cable television channels broadcast live video of the moonwalks, the three broadcast networks aired highlights that were largely confined to late night. ABC squeezed in coverage of the first moonwalk during halftime of Monday Night Football. “The fact is that pictures, no matter how incredibly good their technical quality, of barren moonscapes and floating astronauts become ordinary and even tedious rather quickly,” reported the New York Times.

When the Apollo 17 capsule splashed down in the Pacific Ocean on December 19, the nearly two-week mission was over and the Apollo program was history. A new era of low-orbit manned spaceflight that included the Skylab space station and the space shuttle program followed, but NASA has planned a return voyage to the moon. Nearly 50 years after Apollo 17, NASA’s uncrewed Artemis 1 mission launched in November 2022 as an initial step to landing two astronauts on the moon’s south pole in 2025.

The 243 pounds of lunar soil and rocks returned to Earth by Apollo 17 surpassed all previous hauls and continue to provide scientific insights a half-century later. One of the last unsealed samples was finally opened in March 2022. “These particular samples were collected from a shadowed region of the moon,” Odom says. “When the Artemis program returns to the moon, we will explore other shadowed regions, and these samples serve as analogs for what we can expect to find near the moon’s south pole region.”

Perhaps Apollo 17’s most enduring legacy was an iconic photograph taken with a 70-millimeter Hasselblad camera approximately five hours after launch. One of the crew—exactly who isn’t known—snapped a picture of the full Earth 28,000 miles away. The "Blue Marble" image of the fully lit planet with its green and tan landmasses, sapphire oceans and white clouds and ice caps set against the dark void of space became a symbol for Earth Day and environmental causes.

"Blue Marble" is one of the most widely reproduced images in history. “While the photo didn’t begin the environmental movement,” Odom says, “it did serve as a galvanizing image that for many sparked a reconceptualization of how fragile our home planet really was.”

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