Rising over the battered surface of the moon, Earth loomed in a shimmering arc covered in a swirling skin of clouds.
The image, taken in 1966 by NASA's robotic probe Lunar Orbiter 1, presented a stunning juxtaposition of planet and moon that no earthling had ever seen before.
It was dubbed the Picture of the Century. "The most beautiful thing I'd ever seen," remembered Keith Cowing, who saw it as an 11-year-old and credited it with eventually luring him to work for NASA.
But in the mad rush of discovery, even the breathtaking can get mislaid.
NASA was so preoccupied with getting an astronaut to the moon ahead of the Soviets that little attention was paid to the mountains of scientific data that flowed back to Earth from its early space missions. The data, stored on miles of fragile tapes, grew into mountains that were packed up and sent to a government warehouse with crates of other stuff.
And so they eventually came to the attention of Nancy Evans, a no-nonsense woman with flaming red hair that fit her sometimes-impatient nature. She had been trained as a biologist, but within the sprawling space agency she had found her niche as an archivist.
Evans was at her desk in the 1970s when a clerk walked into her office, asking what he should do with a truck-sized heap of data tapes that had been released from storage.
"What do you usually do with things like that?" she asked.
"We usually destroy them," he replied.
If there is an unsung hero of the moon race, it is the Lunar Orbiter program of 1966 and 1967. There were five unmanned spacecraft, resembling stubby candleholders with 12-foot-diameter solar arrays at their bases.
On board each were two large telescopes that could focus on objects as small as a yard, along with specially built Kodak cameras using 70-millimeter film. An on-board darkroom developed the lunar images and prepared them for transmission back to Earth.
Their mission was to map the entire surface of the moon in preparation for the Apollo landings -- and all five performed magnificently.
Incidental to its mission, Lunar Orbiter 1 took the first pictures of Earth as a full planet. Taken pre-Summer of Love, pre-Watergate, pre-global warming, it was a family photo of a less-stressed home planet.
Altogether, nearly 2,000 frames were photographed by the five missions, each of which ended with a silent crash onto the lunar surface.
But there was a problem. Although the original high-resolution images were saved on 2-inch-wide tape, those pictures weren't seen by the public. The images that scrolled across television screens and appeared on the front pages of newspapers were snapshots of the originals using standard 35-millimeter film. The images were grainy and washed-out, like a poorly tuned television set.
Still, they inspired wonder as humanity for the first time contemplated the surface of another body in space from a front-row seat. In addition to the famous image of Earth, there were pictures of the giant Copernicus crater, the 800-million-year-old impact crater more than two miles deep and 60 miles across.
It was a short-lived moment of glory for the workhorse missions. Two years after the last one, Apollo astronaut Neil Armstrong stepped onto the surface of the moon. With him was a high-resolution Westinghouse TV camera and three exotic Hasselblad still cameras, among other equipment.
The images the astronauts took easily surpassed the Lunar Orbiter shots. But even they eventually migrated into the realm of the ho-hum as the world was inundated with images of moon buggies, lunar golf and the satellite's monotonously barren surface.
By the time of the final Apollo mission in 1972, the American public and Congress had begun to lose interest.
Evans wasn't particularly interested in the moon either when she went to work the next year for the Jet Propulsion Laboratory in La Canada Flintridge.
The daughter of a Colorado physician, she had trained in anatomy and the biological sciences. Her bosses saw something in the determined young woman that made them think she would be perfect for a new job in Washington: straightening out NASA's archives. The mountains of data from the early Mercury, Mariner and Gemini missions had become a jumbled mess.
Evans turned out to be the perfect choice. She was organized and could take care of herself. She knew her mission: to preserve the history of human space exploration.
When the clerk came in to ask about the Lunar Orbiter tapes, she didn't hesitate.
"Do not destroy those tapes," Evans commanded.
She talked her bosses at JPL into storing them in a lab warehouse. "I could not morally get rid of this stuff," said Evans, 71, in an interview at her Sun Valley home.
She had no idea what she was letting herself in for. The full collection of Lunar Orbiter data amounted to 2,500 tapes. Assembled on pallets, they constituted an imposing monolith 10 feet wide, 20 feet long and 6 feet high.
The mountain of tapes was just part of Evans' new burden.