Beware, flat-earthers. Christopher Potter has mounted a powerful assault on your most cherished belief.

In 1948, British astrophysicist Fred Hoyle made an intriguing prediction: “Once a photograph of the Earth, taken from the outside, is available … a new idea as powerful as any in history will be let loose.” With “The Earth Gazers,” his beautifully written overview of our voyage into the heavens, Potter shows us how that cosmic forecast played out. Photographs from space not only allowed us to see the entire planetary sphere suspended like a blue Eden amid a black void, they also informed us that the human species is “intimately connected, even embedded in its home. The more distant our perspective,” writes the author, “seemingly the more intimate.”

It’s a familiar tale, one that the author largely draws from previous histories of aviation, rocketry and space travel. Yet Potter effectively delivers the highlights, maintaining an engaging narrative thread that links all the main players over the course of the 20th century.

He begins with Charles Lindbergh, a college dropout who found his passion in aviation. After some barnstorming and wingwalking, he made the highest marks at the U.S. Army flying school. Spurred by a $25,000 prize, Lindbergh then conquered the Atlantic Ocean in 1927 and gained lifetime fame. “Lindbergh said that he never saw the Earth so clearly … as he did in those early days of flight,” writes Potter. It was a first step toward Hoyle’s vision.

Lindbergh himself imagined the next frontier – rockets – and quickly telephoned rocket pioneer Robert Goddard upon hearing of his test runs. As a teenager, Goddard dreamed of going to Mars. Once it was thought impossible to escape Earth’s gravitational pull, but “Goddard’s genius was to have worked out how,” Potter writes. “His brilliant concept was the multistage rocket propelled by liquid fuel.” But, though he was a brilliant inventor, he was a lousy engineer. Many of Goddard’s rockets blew up, sputtered out or failed to launch through the 1930s.

As a result, the impetus in rocketry moved to Europe, particularly Germany, where wunderkind Wernher von Braun was designing his country’s rockets and overseeing a budget of 11 million Reichsmarks before he turned 24. His personal goal was to go into space, but he dutifully advanced Hitler’s mandate to attack London. His rockets were manufactured in a series of tunnels carved out of the Harz mountains. There, thousands of POWs and concentration-camp workers labored under conditions that resembled Dante’s Inferno, 20 dying each day from disease, accident, starvation or random killings by the guards. The United States ultimately profited from this tragic legacy. At the war’s end, von Braun packed up his documentation and achieved his aim of going to America to build a space rocket.

No longer top dog, von Braun faced competition from the U.S. military and other government agencies. It was an internal tempest that slowed the American effort, allowing the Soviet Union to take the lead in rocketry and launch the first satellite into space – which may have been a blessing in disguise, according to Potter: “If von Braun had got his satellite into orbit first . . . the space race would surely have taken a different course. It seems highly unlikely that the American public of the time would have so readily funded such a costly enterprise without the motivating force of fear.”

The book travels through “The Right Stuff” territory – swiftly moving from Projects Mercury and Gemini to the Apollo program. Potter also takes a puzzling detour to cover atheist Madalyn Murray O’Hair’s life. While she was a thorn in NASA’s side with her constant challenges to keep God out of astronauts’ mouths, this section appears to be from another book altogether. More captivating are the gossipy space stories. When urine was dumped from a spacecraft, the droplets froze and glittered like diamonds; astronaut Wally Schirra called the display “Constellation Urion.” After Gemini X, Mike Collins “submitted his travel expenses: three days at $8 a day.” And the most bad-tempered mission was Apollo 7, whose crew never flew again.

Surprisingly, taking photographs in space was not a top NASA priority at first, denigrated as being too touristy. But that changed with Gemini IV, when Richard Underwood, the man in charge of NASA photography, convinced the astronauts that the endeavor would be their “key to immortality.” Eventually, writes Potter, “it gave them a rare sense of independence and the opportunity to be more than just a man in a can; to be artists.”

The first pictures of a full Earth from space, by both the Lunar Orbiter and an Earth-orbiting satellite in 1966, had little impact, probably because of the poor quality. But on Apollo 8, the first manned spacecraft to circle the moon, Bill Anders snapped a vivid, color picture of Earth rising over the lunar surface. On the way out, the Apollo 8 astronauts had been the first to see the entire Earth in a single glance. Where did I see this before, thought Anders. “And [he] remembers that it was three months earlier, at the premiere of Kubrick’s ‘2001: A Space Odyssey,'” Potter writes.

With Apollo 11, the mission that first landed on the moon, the book returns to Lindbergh, then 67 years old, who was on hand to watch the launch. From 1968 to 1972, a total of 24 astronauts either walked on the moon or viewed the full Earth from space – both experiences appeared to have been life-altering. Afterward, some of these Earth gazers divorced; others turned to poetry, art, philosophy and religion.

One even became a sort of hippie. Apollo 9 astronaut Rusty Schweickart grew a beard, hung out with yogis and told Time magazine that he had lost his “identity as an American astronaut. … National boundaries became meaningless and arbitrary, but also the boundary between self and not-self.” Astronaut Ed Mitchell, too, came to think the universe was “in some way conscious.”

How did Hoyle’s prediction pan out for those of us who remained behind? For one, “Earthrise,” Apollo 8’s famous photograph, became one of the most reproduced pictures of all time. Wilderness photographer Galen Rowell called it “the most influential environmental photograph ever taken.” For many, it vividly illustrates our planet’s fragility. Perhaps it’s no coincidence that the Earth Day movement arose soon after. “Might this be another reason to travel into space,” Potter writes, “in order to experience what an alien might experience: to see ourselves from the outside?”

If so, we vitally need a renewal of that enlightenment as we approach the 50th anniversary of the moon landing. Decades after his Apollo 8 flight, Jim Lovell warned us that “the mind easily forgets. … People get back to the way they lived before – wars and disruption and human cruelty.”