Fifty years ago, astronauts walked on the moon for the first time. Apollo 11’s success—just 66 years after the Wright brothers’ first flight—showcased humankind’s moxie and ingenuity. It was one of history’s most astounding moments, and it was just the beginning. The beginning of a new era in humanity’s vision of its horizons, of the places we could explore and might even inhabit. It was no longer sufficient to describe us as “Earthlings.” We were spacefarers. The very act of reaching the moon exalted the human race, yielding confidence that we would indeed push deeper into space.