On this day, 50 years ago, three men were hurtling toward the most distant place the human race has ever been.
When the lunar module touched down on the Moon on July 20, 1969, the Apollo 11 mission transformed what we mean when we talk about the world we live in.
One year before, we were captivated by "Earthrise," the famous photo taken by Apollo 8's William Anders from low lunar orbit that condensed the birthplace, home and final resting place of every human who had ever lived into a blue-and-white marble floating silently in space, dwarfed by the gray expanse of the Moon beneath it.
After landing on the Moon, Neil Armstrong took his camera and photographed Buzz Aldrin's footprint in the lunar dust — an unmistakable symbol of humanity's impact, quite literally, on another world — an impression so indelible that it will take about a million years of cosmic radiation to scour it away.
Decades later, it was the unmanned space probe Voyager 1 sending back a grainy image from the vast beyond — the "pale blue dot" of Earth as seen from nearly 4 billion miles away — that shook us. How can you see this incredible planet we live on as a single pixel and not feel awe: at how impossibly small we are in an incomprehensibly huge cosmos, at how amazing it is we can take a self-portrait from the edge of the solar system, at how vulnerable our cradle of life is.
Space exploration is often likened to the so-called Age of Discovery, when Europeans built tall ships and sailed them to lands they'd never seen before and called them "new" — irrespective of whether there were already non-European people living there.
Of course, space exploration is completely different.
The "New World" that Columbus, Vespucci, Tasman and their contemporaries "discovered" turned out to be not so different from their "Old World." Conquistadors and colonists found they could breathe the air, till the soil, and hunt and fish just as well in the Americas as they could in Europe. For all the epithets like "savage" and "aborigine" and all the blood they spilled to impose a European sense of order in the lands they claimed, the people they encountered were human beings like them, living not so dissimilar lives.
Armstrong and Aldrin found the Moon more or less as they expected: It's an airless rock, pocked by impact craters, blasted by solar rays, utterly inhospitable to human life. While as recently as the 1950s, some cosmic thinkers held out hope that they could find a "New World" in the night sky, just as their forebears had found across the ocean centuries earlier, the advent of space probes and advanced telescopes put that to rest.
In his 1954 short story "All Summer in a Day," Ray Bradbury famously envisioned how human colonists would live on a lush, perpetually rainy Venus — the brightest object in a moonless night sky, Earth's closest planetary neighbor, its "twin." When the unmanned Mariner 2 spacecraft conducted a flyby of Venus just eight years later, it sent back data describing a superheated atmosphere of about 900 degrees Fahrenheit. As if that weren't enough to dash Bradbury's dreams of a soggy second Earth, subsequent probes discovered Venus was swaddled in toxic clouds, and a visitor to the surface would be under pressure similar to what they would experience on the ocean floor. More than one spacecraft sent to uncover data on Earth's hellish neighbor world was crushed like a tin can by its sulfurous atmosphere.
There are, needless to say, no plans to attempt human exploration of Venus, much less large-scale settlement.
Many futurists hold out hope that humans will eventually settle on Mars. It's almost certainly the best prospect in the solar system. But even if it's possible, establishing a Mars colony would be orders of magnitude more challenging than establishing colonies in the "New World" here on Earth.
Unlike on Venus, the atmosphere on Mars won't broil and crush you at the same time. But it's no more breathable, and to make matters worse, the Martian soil is poisoned as well. Gravity on Mars is less than half what it is on Earth, which could interfere with normal growth and healing processes. The thin atmosphere and weak magnetic field mean there would be little protection from dangerous, cancer-causing solar radiation. The climate is so cold that at times, carbon dioxide falls from the sky as dry ice.
Truly, in the words of Dorothy in "The Wizard of Oz," there's no place like home.
But in dispelling the comparison, we don't mean to discount the value of venturing into the unknown. In fact, it's necessary.
Space truly is the final frontier. It's a monumental challenge, one that the laws of physics themselves suggest we may never quite master. But it's only by crossing that threshold that we can expand our horizons.
Human history is a tale of fitful progress. For every terrible news story and every pang of existential dread it makes us feel, it's worth remembering how much different things are today than they were 50 years ago, or 100 years, or 500, or 3,000.
One of the favorite aphorisms of the Rev. Martin Luther King Jr., who died the year before a man walked on the Moon, was that "the arc of the moral universe is long, but it bends toward justice."
The arc doesn't bend itself. It took 16 million Allied lives to bend the arc toward the justice served at Nuremberg and Tokyo. It took the blood, sweat and tears of marchers on the Edmund Pettis Bridge, Freedom Riders in Bull Connor's Birmingham, and thousands more across the United States to bend the arc toward civil rights for Americans of every race. It will take a worldwide effort far beyond the "space race" of the '50s and '60s to bend the arc toward climate stability on Earth, as atmospheric carbon and ocean acidification soar toward dangerous levels.
Our existence is confined to a single pixel, that pale blue dot. If it goes away, we're finished. We have a moral imperative to protect it. We have a moral imperative to protect our future as a species by transcending it.
The last human beings to walk on the Moon climbed back inside their lunar module and blasted off on Dec. 14, 1972. Mars — hundreds of times more distant than the Moon even at its nearest point — remains virgin soil, aside from a few unmanned landers and rovers.
Expanding human civilization onto another world isn't as simple as sailing across the sea and planting a flag. In fact, maybe it's impossible. The obstacles are immense. But we owe it to our grandchildren and great-grandchildren to try — more aptly, to begin trying, knowing that we may not succeed within our own lifetimes, knowing it may be up to them to take up the challenge, knowing perhaps no one will ever succeed.
"We choose to go to the Moon in this decade, and do the other things," President John F. Kennedy said in 1962, speaking in Houston of the ambitious young American space program, "not because they are easy, but because they are hard."
We can only hope that this 50th anniversary of Apollo 11 will help to rekindle that spirit of adventure, the willingness to test the limits of possibility and the ingenuity it takes to realize the fantastic.
Kennedy didn't live to see a man walk on the Moon. But his legacy stands, half a century later, as the most incredible achievement in human history.
Now, all we have to do is surpass it.
You count on us to stay informed and we depend on you to fund our efforts. Quality local journalism takes time and money. Please support us to protect the future of community journalism.