Like its cousin, 1848, in which Europe was convulsed with revolution, 1968 was a year of tumult. It was the year of the Tet Offensive in the Vietnam War, the murder of the Rev Dr Martin Luther King Jr and the rioting that followed in America’s cities, the murder two months later of Robert F Kennedy, the student riots in Paris and strikes in France, the Soviet invasion of Czechoslovakia that crushed the “Prague Spring,” the youth protests at the Democratic National Convention in Chicago, and the hundreds of deaths in Mexico City at Tlatelolco Square just before the Olympics.

Yet if 1968 witnessed too numerous examples of the smallness of humanity or at least of individual humans, the year would close from the void of outer space with a resounding proof of our smallness in the universe – and, ironically, serve as a unifying vision and a force for good.

For it was also the era of the space race between the US and USSR, and NASA was working to fulfill Kennedy’s dream of an American walking on the moon and returning safely by the end of the decade. As time grew short, the rumor grew that the Soviets were seeking a translunar flight by the end of 1968, and so NASA changed a regular testing mission to become a flight around the moon: Apollo 8.

Launched on December 21, 1968, Apollo 8 marked the first time that humans had seen the far side of the moon and the first time that humans saw “Earthrise,” in a famous picture that sparked the nascent environmental movement. For the first time, those on Earth could see the whole of the planet at once – and think about our common humanity and our common fragility. As astronaut James Lovell said recently, “we saw the Earth as it really is”: a small planet, insignificant in size compared to the galaxy, still less the universe.

'We saw the Earth as it really is': a small planet, insignificant in size compared to the galaxy, still less the universe

The crew arrived in lunar orbit on Christmas Eve after 68 hours of flight and, leaving its ninth orbit, made a television broadcast. About a billion people saw the broadcast in some form, the most watched event in history. After describing the Moon, the crew read the first ten verses of Genesis, concluding with “And God saw that it was good”.

Despite everything in 1968, the Earth was good, and the astronauts closed by wishing everyone: “good night, good luck, a Merry Christmas and God bless all of you — all of you on the good Earth”. Good, and fragile, and it required keeping, far better than had been done with war or racial discrimination or environmental pollution. A small planet, insignificant in size compared to the galaxy, but still our home and one perfectly suited for life, with water and air and soil and a sun nearby to give warmth.

All three astronauts – Frank Borman, Lovell, and William Anders – are living, and the anniversary of the flight was recently commemorated at a service at Washington’s National Cathedral. Presiding Bishop Michael Curry (who earlier this year preached at the royal wedding), wondered in his sermon that “if when they saw it, and then later we saw it, and when they read from Genesis, if God kind of gave a cosmic smile. And I wonder if God said, ‘Now y’all see what I see.’” And, as Curry noted, “This is God’s world. We are here because the great God Almighty looked back and said, ‘I’m lonely; I’ll make me a world.’”

Facebook Twitter Pinterest William Anders, James Lovell and Frank Borman at the Museum of Science and Industry in Chicago. Photograph: JB Spector/AP

What did it all mean? During the flight itself, the scientific view prevailed. Borman first described the moon on television as “a vast, lonely, forbidding expanse of nothing”. But safe return and the passage of time led to more philosophical reflections. James Lovell said that “in this cathedral, my world exists within these walls. But seeing the Earth at 240,000 miles, my world suddenly expanded to infinity”. Cosmically insignificant, we became significant because of our responsibility to care for this planet entrusted to us; and seeing the world as Apollo 8 did, floating in the universe, awakened a new global consciousness.

It is one thing merely to marvel at technological achievement, still another to recall the sense of national purpose that it restored after a terrible year of violence and war and the environmental awakening it sparked. Remembering the flight of Apollo 8 should engender reflection but not give way to despair as to what has been lost. Instead, it should give hope, for in the cosmic scheme, 50 years is the blink of an eye. Lovell perhaps summed it up best: “God gave mankind a stage upon which to perform; how the play ends is up to us.”

Humanity can still redeem the promise of this remarkable voyage.