We are naturally eager to find additional signs of vulcanism on other worlds. On Europa, the second of the Galilean moons of Jupiter and Io's neighbor, there are no volcanic mountains at all; but molten ice—liquid water—seems to have gushed to the surface through an enormous number of crisscrossing dark markings before freezing. And further out, among the moons of Saturn, there are signs that liquid water has gushed up from the interior and wiped away impact craters. Still, we have never seen anything that might plausibly be an ice volcano in either the Jupiter or Saturn systems. On Triton, we may have observed nitrogen or methane vulcanism.
The volcanos of other worlds provide a stirring spectacle. They enhance our sense of wonder, our joy in the beauty and diversity of the Cosmos. But these exotic volcanos perform another service as well: They help us to know the volcanos of our own world—and perhaps will help one day even to predict their eruptions. If we cannot understand what's happening in other circumstances, where the physical parameters are different, how deep can our understanding be of the circumstance of most concern to us? A general theory of vulcanism must cover all cases. When we stumble upon vast volcanic eminences on a geologically quiet Mars; when we discover the surface of Venus wiped clean only yesterday by floods of magma; when we find a world melted not by the heat of radioactive decay, as on Earth, but by gravitational tides exerted by nearby worlds; when we observe sulfur rather than silicate vulcanism; and when we begin to wonder, in the moons of the outer planets, whether we might be viewing water, ammonia, nitrogen, or methane vulcanism—then we are learning what else is possible.
CHAPTER 13: THE GIFT OF APOLLO
The gates of Heaven are open wide;
Off I ride . . .
—CH'U TZ'U /ATTRIBUTED TO CH'U YUAN),
"THE NINE SONGS," SONG V, "THE GREAT LORD OF LIVES"
(CHINA, CA. THIRD CENTURY B.C.)
It's a sultry night in July. You've fallen asleep in the armchair. Abruptly, you startle awake, disoriented. The television set is on, but not the sound. You strain to understand what you're seeing. Two ghostly white figures in coveralls and helmets are softly dancing under a pitch-black sky. They make strange little skipping motions, which propel them upward amid barely perceptible clouds of dust. But something is wrong. They take too long to come down. Encumbered as they are, they seem to be flying a little. You rub your eyes, but the dreamlike tableau persists.
Of all the events surrounding Apollo 11's landing on the Moon on July 20, 1969, my most vivid recollection is its unreal quality. Neil Armstrong and Buzz Aldrin shuffled along the gray, dusty lunar surface, the Earth looming large in their sky, while Michael Collins, now the Moon's own moon, orbited above them in lonely vigil. Yes, it was an astonishing technological achievement and a triumph for the United States. Yes, the astronauts displayed death-defying courage. Yes, as Armstrong said as he first alighted, this was a historic step for the human species. But if you turned off the by-play between Mission Control and the Sea of Tranquility, with its deliberately mundane and routine chatter, and stared into that black-and-white television monitor, you could glimpse that we humans had entered the realm of myth and legend.
We knew the Moon from our earliest days. It was there when our ancestors descended from the trees into the savannahs, when we learned to walk upright, when we first devised stone tools, when we domesticated fire, when we invented agriculture and built cities and set out to subdue the Earth. Folklore and popular songs celebrate a mysterious connection between the Moon and love. The word "month" and the second day of the week are both named after the Moon. Its waxing and waning—from crescent to full to crescent to new—was widely understood as a celestial metaphor of death and rebirth. It was connected with the ovulation cycle of women, which has nearly the same period—as the word "menstruation" (Latin mensis = month, from the word "to measure") reminds us. Those who sleep in moonlight go mad; the connection is preserved in the English word "lunatic." In the old Persian story, a vizier renowned for his wisdom is asked which is more useful, the Sun or the Moon. "The Moon," he answers, "because the Sun shines in daytime when it's light out anyway." Especially when we lived out-of-doors, it was a major—if oddly intangible—presence in our lives.
The Moon was a metaphor for the unattainable: "You plight as well ask for the Moon," they used to say. Or "You can no more do that than fly to the Moon." For most of our history, eve had no idea what it was. A spirit? A god? A thing? It didn't look like something big far away, but more like something small nearby—something the size of a plate, maybe, hanging in the sky a little above our heads. Ancient Greek philosophers debated the proposition "that the Moon is exactly as large as it looks" (betraying a hopeless confusion between linear and angular size). Walking on the Moon would have seemed a screwball idea; it made more sense to imagine somehow climbing up into the sky on a ladder or on the back of a giant bird, grabbing the Moon, and bringing it down to Earth. Nobody ever succeeded, although there were myths aplenty about heroes who had tried.
Not until a few centuries ago did the idea of the Moon as a place, a quarter-million miles away, gain wide currency. And in that brief flicker of time, we've gone from the earliest steps in understanding the Moon's nature to walking and joy-riding on its surface. We calculated how objects move in space; liquefied oxygen from the air; invented big rockets, telemetry, reliable electronics, inertial guidance, and much else. Then we sailed out into the sky.
I was lucky enough to be involved in the Apollo program, but I don't blame people who think the whole thing was faked in a Hollywood movie studio. In the late Roman Empire, pagan philosophers had attacked Christian doctrine on the ascension to Heaven of the body of Christ and on the promised bodily resurrection of the dead—because the force of gravity pulls down all "earthly bodies." St. Augustine rejoined: "If human skill can by some contrivance fabricate vessels that float, out of metals which sink. . . how much more credible is it that God, by some hidden mode of operation, should even more certainly effect that these earthly masses be emancipated" from the chains that bind them to Earth? That humans should one day discover such a "mode of operation" was beyond imagining. Fifteen hundred years later, we emancipated ourselves.
The achievement elicited an amalgam of awe and concern. Some remembered the story of the Tower of Babel. Some, orthodox Moslems among them, felt setting foot on the Moon's surface to be impudence and sacrilege. Many greeted it as a turning point in history.
The Moon is no longer unattainable. A dozen humans, all Americans, have made those odd bounding motions they called "moonwalks" on the crunchy, cratered, ancient gray lava—beginning on that July day in 1969. But since 1972, no one from any nation has ventured back. Indeed, none of us has gone anywhere since the glory days of Apollo except into low Earth orbit—like a toddler who takes a few tentative steps outward and then, breathless, retreats to the safety of his mother's skirts.
Once upon a time, we soared into the Solar System. For a few years. Then we hurried back. Why? What happened? What was Apollo really about?
The scope and audacity of John Kennedy's May 25, 1961 message to a joint session of Congress on "Urgent National Needs"—the speech that launched the Apollo program—dazzled me. We would use rockets not yet designed and alloys not yet conceived, navigation and docking schemes not yet devised, in order to send a man to an unknown world—a world not yet explored, not even in a preliminary way, not even by robots—and we would bring him safely back, and we would do it before the decade was over. This confident pronouncement was made before any American had even achieved Earth orbit.
As a newly minted Ph.D., I actually thought all this had something centrally to do with science. But the President did not talk about discovering the origin of the Moon, or even about bringing samples of it back for study. All he seemed to be interested in was sending someone there and bringing him home. It was a kind of gesture. Kennedy's science advisor, Jerome Wiesner, later told me he had made a deal with the President: If Kennedy would not claim that Apollo was a
bout science, then he. Wiesner, would support it. So if not science, what?
The Apollo program is really about politics, others told me. This sounded more promising. Nonaligned nations would be tempted to drift toward the Soviet Union if it was ahead in space exploration, if the United States showed insufficient "national vigor." I didn't follow. Here was the United States, ahead of the Soviet Union in virtually every area of technology—the world's economic, military, and, on occasion, even moral leader—and Indonesia would go Communist because Yuri Gagarin beat John Glenn to Earth orbit? What's so special about space technology? Suddenly I understood.
Sending people to orbit the Earth or robots to orbit the Sun requires rockets—big, reliable, powerful rockets. Those same rockets can be used for nuclear war. The same technology that transports a man to the Moon can carry nuclear warheads halfway around the world. The same technology that puts an astronomer and a telescope in Earth orbit can also put up a laser "battle station." Even back then, there was fanciful talk in military circles, East and West, about space as the new "high ground," about the nation that "controlled" space "controlling" the Earth. Of course strategic rockets were already being tested on Earth. But heaving a ballistic missile with a dummy warhead into a target zone in the middle of the Pacific Ocean doesn't buy much glory. Sending people into space captures the attention and Imagination of the world.
You wouldn't spend the money to launch astronauts for this reason alone, but of all the ways of demonstrating rocket potency, this one works best. It was a rite of national manhood; the shape of the boosters made this point readily understood without anyone actually having to explain it. The communication seemed to be transmitted from unconscious mind to unconscious mind without the higher mental faculties catching a whiff of what was going on.
My colleagues today—struggling for every space science dollar—may have forgotten how easy it was to get money for "space" in the glory days of Apollo and just before. Of many examples, consider this exchange before the Defense Appropriations Subcommittee of the House of Representatives in 1958, only a few months after Sputnik 1. Air Force Assistant Secretary Richard E. Horner is testifying; his interlocutor is Rep. Daniel J. Flood (Democrat of Pennsylvania):
HORNER: [W]hy is it desirable from the military point of view to have a man on the moon? Partly, from the classic point of view, because it is there. Partly because we might be afraid that the U.S.S.R. might get one there first and realize advantages which we had not anticipated existed there . . .
FLOOD: [I]f we gave you all the money you said was necessary, regardless of how much it was, can you in the Air Force hit the moon with something, anything, before Christmas?
HORNER: I feel sure we can. There is always a certain amount of risk in this kind of undertaking, but we feel that we can do that; yes, sir.
FLOOD: Have you asked anybody in the Air Force or the Department of Defense to give you enough money,
hardware, and people, starting at midnight tonight, to chip a. piece out of that ball of green cheese for a Christmas present to Uncle Sam? Have you asked for that?
HORNER: We have submitted such a program to the Office of the Secretary of Defense. It is currently under consideration.
FLOOD: I am for giving it to them as of this minute, Mr. Chairman, with our supplemental, without waiting for somebody downtown to make up his mind to ask for it. If this man means what he says and if he knows what he is talking about—and I think he does—then this committee should not wait five minutes more today. We should give him all the money and all the hardware and all the people he wants, regardless of what anybody else says or wants, and tell him to go up on top of some hill and do it without any question.
When President Kennedy formulated the Apollo program, the Defense Department had a slew of space projects under development—ways of carrying military personnel up into space, means of conveying them around the Earth, robot weapons on orbiting platforms intended to shoot down satellites and ballistic missiles of other nations. Apollo supplanted these programs. They never reached operational status. A case can be made then that Apollo served another purpose—to move the U.S.—Soviet space competition from a military to a civilian arena. There are some who believe that Kennedy intended Apollo as a substitute for an anus race in space. Maybe.
For me, the most ironic token of that moment in history is the plaque signed by President Richard M. Nixon that Apollo 11 took to the Moon. It reads: "We came in peace for all mankind." As the United States was dropping 7½ megatons of conventional explosives on small nations in Southeast Asia, we congratulated ourselves on our humanity: We would harm no one on a lifeless rock. That plaque is there still, attached to the base of the Apollo 11 Lunar Module, on the airless desolation of the Sea of Tranquility. If no one disturbs it, it will still be readable a million years from now.
Six more missions followed Apollo 11, all but one of which successfully landed on the lunar surface. Apollo 17 was the first to carry a scientist. As soon as he got there, the program was canceled. The first scientist and the last human to land on the Moon were the same person. The program had already served its purpose that July night in 1969. The half-dozen subsequent missions were just momentum.
Apollo was not mainly about science. It was not even mainly about space. Apollo was about ideological confrontation and nuclear war—often described by such euphemisms as world "leadership" and national "prestige." Nevertheless, good space science was done. We now know much more about the composition, age, and history of the Moon and the origin of the lunar landforms. We have made progress in understanding where the Moon came from. Some of us have used lunar cratering statistics to better understand the Earth at the time of the origin of life. But more important than any of this, Apollo provided an aegis, an umbrella under which brilliantly engineered robot spacecraft were dispatched throughout the Solar System, making that preliminary reconnaissance of dozens of worlds. The offspring of Apollo have now reached the planetary frontiers.
If not for Apollo—and, therefore, if not for the political purpose it served—I doubt whether the historic American expeditions of exploration and discovery throughout the Solar System would have occurred, The Mariners, Vikings, Pioneers, Voyagers ,and Galileo are among the gifts of Apollo. Magellan and Cassini are more distant descendants. Something similar is true for the pioneering Soviet efforts in Solar System exploration, including the first soft landings of robot spacecraft—Luna 9, Mars 3, Venera 8-on other worlds.
Apollo conveyed a confidence, energy, and breadth of vision that did capture the imagination of the world. That too was part of its purpose. It inspired an optimism about technology, an enthusiasm for the future. If we could fly to the Moon, as so many have asked, what else were we capable of? Even those who opposed the policies and actions of the United States—even those who thought the worst of us—acknowledged the genius and heroism of the Apollo program. With Apollo, the United States touched greatness.
When you pack your bags for a big trip, you never know what's in store for you. The Apollo astronauts on their way to and from the Moon photographed their home planet. It was a natural thing to do, but it had consequences that few foresaw. For the first time, the inhabitants of Earth could see their world from above—the whole Earth, the Earth in color, the Earth as an exquisite spinning white and blue ball set against the vast darkness of space. Those images helped awaken our slumbering planetary consciousness. They provide incontestable evidence that we all share the same vulnerable planet. They remind us of what is important and what is not. They were the harbingers of Voyager's pale blue dot.
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 of 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."