Pale Blue Dot - Carl Sagan [77]
We may have found that perspective just in time, just as our technology threatens the habitability of our world. Whatever the reason we first mustered the Apollo program, however mired it was in Cold War nationalism and the instruments of death, the inescapable recognition of the unity and fragility of the Earth is its clear and luminous dividend, the unexpected final gift of Apollo. What began in deadly competition has helped us to see that global cooperation is the essential precondition for our survival.
Travel is broadening.
It’s time to hit the road again.
CHAPTER 14
EXPLORING OTHER WORLDS AND PROTECTING THIS ONE
The planets, in their various stages of development, are subjected to the same formative forces that operate on our earth, and have, therefore, the same geologic formation, and probably life, of our own past, and perhaps future; but, further than this, these forces are acting, in some cases, under totally different conditions from those under which they operate on the earth, and hence must evolve forms different from those ever known to man. The value of such material as this to the comparative sciences is too obvious to need discussion.
ROBERT H. GODDARD, NOTEBOOK (1907)
For the first time in my life, I saw the horizon as a curved line. It was accentuated by a thin seam of dark blue light—our atmosphere. Obviously, this was not the “ocean” of air I had been told it was so many times in my life. I was terrified by its fragile appearance.
—ULF MERBOLD, GERMAN SPACE SHUTTLE ASTRONAUT (1988)
When you look down at the Earth from orbital altitudes, you see a lovely, fragile world embedded in black vacuum. But peering at a piece of the Earth through a spacecraft porthole is nothing like the joy of seeing it entire against the backdrop of black, or—better—sweeping across your field of view as you float in space unencumbered by a spacecraft. The first human to have this experience was Alexei Leonov, who on March 18, 1965, left Voskhod 2 in the original space “walk”: “I looked down at the Earth,” he recalls, “and the first thought that crossed my mind was ‘The world is round, after all.’ In one glance I could see from Gibraltar to the Caspian Sea … I felt like a bird—with wings, and able to fly.”
When you view the Earth from farther away, as the Apollo astronauts did, it shrinks in apparent size, until nothing but a little geography remains. You’re struck by how self-contained it is. An occasional hydrogen atom leaves; a pitter-patter of cometary dust arrives. Sunlight, generated in the immense, silent thermonuclear engine deep in the solar interior, pours out of the Sun in all directions, and the Earth intercepts enough of it to provide a little illumination and enough heat for our modest purposes. Apart from that, this small world is on its own.
From the surface of the Moon you can see it, perhaps as a crescent, even its continents now indistinct. And from the vantage point of the outermost planet it is a mere point of pale light.
From Earth orbit, you are struck by the tender blue arc of the horizon—the Earth’s thin atmosphere seen tangentially. You can understand why there is no longer such a thing as a local environmental problem. Molecules are stupid. Industrial poisons, greenhouse gases, and substances that attack the protective ozone layer, because of their abysmal ignorance, do not respect borders. They are oblivious of the notion of national sovereignty. And so, due to the almost mythic powers of our technology (and the prevalence of short-term thinking), we are beginning—on continental and on planetary scales—to pose a danger to ourselves. Plainly, if these problems are to be solved, it will require many nations acting in concert over many years.
I’m struck again by the irony that spaceflight—conceived in the cauldron of nationalist rivalries and hatreds—brings with it a stunning transnational vision. You spend even a little time