When Clarke released his story in 1951, humanity had already experienced the U.S.'s wartime use of two atomic bombs, along with several atomic tests. As people began to understand the devastating power of atomic weaponry, many science fiction authors started to imagine the possible consequences of atomic warfare in tales like this one. When Marvin sees his first earthrise, he mentions the atomic nature of the destruction. The narrator notes, ‘‘the glow of dying atoms was still visible, a perennial reminder of the ruinous past.’’ Radioactive atoms take a long time to decay, remaining visible from the moon even though the humans who engaged in the atomic war are long gone. Clarke also understood the processes through which atomic radiation would eventually be cleansed from Earth. The narrator states, ‘‘[t]he winds and the rains would scour the poisons from the burning lands and carry them to the sea.’’ It is in the vast oceans that the radiation would finally become diluted enough so that ‘‘they could harm no living things.’’

The characters in Clarke's narrative endure a form of planetary exile. Marvin, having been born in the lunar colony, has never set foot on Earth. The narrator highlights this fact when describing Marvin’s initial glimpse of Earth: "There in that shining crescent were all the wonders that he had never known." Marvin has only encountered Earth through books, a realization that deepens his sense of "the anguish of exile." This feeling intensifies as he observes the part of Earth that should be dark, "gleaming faintly with an evil phosphorescence," and recalls the tales of the atomic war that left his parents marooned on the moon.

This lunar exile is unlike any previous human experience. Throughout history, people have faced exile, but often with the possibility of returning. However, the inhabitants of the moon colony lack this option. In Earth's final days of destruction, they come to understand this reality and recognize that "they were alone at last, as no men had ever been alone before, carrying in their hands the future of the race."

The current inhabitants of the colony are destined never to set foot on Earth again. Marvin states, "It would be centuries yet before that deadly glow died from the rocks and life could return again to fill that silent, empty world." In the aftermath of Earth's destruction, the colony's members couldn't afford to dwell on the long-term consequences; their immediate focus was on survival. Having relied heavily on Earth for supplies, it was a significant shock when "the colony had learned at last that never again would the supply ships come flaming down through the stars with gifts from home." For several years, the lunar settlers struggled to establish a sustainable life on the moon using the resources they had, and eventually, they succeeded. The narrator notes that "this little oasis of life was safe against the worst that Nature could do."

Once their short-term survival was secured, the colony's inhabitants realized they needed to do more. They had to pass on their cultural and scientific knowledge, along with their aspiration to return to Earth, to their children, who would, in turn, continue this mission with their own offspring. When Marvin's father takes him to see the devastated Earth, Marvin grasps that this rite of passage is vital for the continuation of humanity, even though he must accept that he will never see Earth himself. "He would never walk beside the rivers of that lost and legendary world. . . . Yet one day . . . his children’s children would return to claim their heritage."