Narrator: We were wanderers from the beginning. We knew every stand of tree for a hundred miles. When the fruits and nuts were ripe, we were there. We followed the herds in their annual migrations. We rejoiced in fresh meat. Through stealth, faint, ambush, and main force assault. A few of us cooperating accomplished what many of us, each hunting alone, could not. We depended on one another.
Making it on our own was as ludicrous to imagine as was settling down. for 99.9% of the time since our species came to be we were hunters and foragers, wanderers on the savannas and the steps. The frontier was everywhere. We were bounded only by the earth, and the ocean, and the sky. In the last 10,000 years, an instant in our long history, we've abandoned the nomadic life. For all its material advantages, the sedentary life has left us edgy, unfulfilled. The open road still softly calls like a nearly forgotten song of childhood.
We invest far-off places with a certain romance. The appeal, I suspect, has been meticulously crafted by natural selection as an essential element in our survival. Long summers, mild winters, rich harvests, plentiful game, non of them lasts forever. It is beyond our power as to predict the future. Catastrophic events have a way of sneaking up on us, of catching us unaware. Your own life, or your band's, or even your species might be owed to a restless few drawn, by a craving they can hardly articulate or understand, to undiscovered lands and new worlds.
To ancient Greeks and Romans, the known world comprised Europe and attenuated Asia and Africa all surrounded by an impassible world ocean. Travelers might encounter inferior beings called barbarians or superior beings called gods, but there were not many many gods, at least at first, perhaps only a few dozen. They lived on mountains, under the earth, in the sea, or up there in the sky. They sent messages to people, intervened in human affairs, and interbred with us. As time passed, as the human exploratory capacity hit its stride, there were surprises. Barbarians could be fully as cleaver as Greeks and Romans. Africa and Asia were larger than anyone had guessed.
The world ocean was not impassible. Three new continents existed; Had been settled by Asians in ages past and the news had never reached Europe. Also, the gods were disappointingly hard to find. Since we first emerged a few million years ago in east Africa we've meandered our way around the planet. There are now people on every continent and the remotest islands, from pole to pole, from Mount Everest to the Dead Sea, on the ocean bottoms and even, occasionally, in residence 200 miles up humans, like the gods of old, living in the sky.
These days, there seems to be nowhere left to explore, victims of their very success, the explorers now, pretty much, stay home. Vast migrations of people, some voluntary, most not, have shaped the human condition. More of us flee from war, oppression, and famine today than at any other time in human history. As the Earth's climate changes in the coming decades there are likely to be far greater numbers of environmental refugees.
Better places will always call to us. Tides of people will continue to ebb and flow across the planet, but the lands we run to now have already been settled. Other people, often unsympathetic to our plight, are there before us. Maybe it's a little early. Maybe the time is not quite yet, but those are the worlds, promising untold opportunities, beckon. In the last few decades the United States and the former Soviet Union have accomplished something stunning and historic. A close-up examination of all those points of light from Mercury to Saturn, that moved our ancestors to wonder and to science. Since the advent of successful interplanetary flight in 1962, our machines have flown by, or orbited, or landed more than seventy new worlds. We have wandered among the wanderers.
We have found vast volcanic eminences that dwarf the highest mountain on earth, ancient river valleys on two planets, enigmatically one too cold and the other too hot for running water; A giant planet with an interior of liquid metallic hydrogen into which a thousand Earths would fit; Whole moons that have melted; A cloud covered place with an atmosphere of corrosive acids, where even the high plateaus are above the melting point of lead; Ancient surfaces on which a faithful record of the violent formation of the solar system is engraved; Refugee ice worlds from the trans-plutonium depths; Exquisitely patterned ring systems marking the subtle harmonies of gravity; And a world surrounded by clouds of complex organic molecules like those, that in the earliest history of our planet, led to the origin of life.
Silently, they orbit the sun waiting. We have uncovered wonders undreamed by our ancestors who first speculated on the nature of those wandering lights in the night sky. We have probed the origins of our planet and ourselves. By discovering what else is possible, by coming face to face with alternative fates of worlds more or less like our own we have begun to better understand the Earth. Every one of those worlds is lovely and instructive. but so far as we know, they are also, every one of them, desolate and barren. Out there, there are no better places, so far at least. During the Viking robotic missions, beginning in July 1976, in a certain sense, I spent a year on Mars. I examined the boulders and sand dunes; the sky, red even at high noon; the ancient river valleys; the soaring volcanic mountains; the fierce wind erosion; the laminated polar terrain; the two dark potato-shaped moons, but there was no life, not a cricket, or a blade of grass, or even, so far as we can tell for sure, a microbe.
Life is a comparative rarity. You can survey dozens of worlds and find that in only one of them does life arise and evolve and persist. Neptune lies a million times further from Earth than New York City is from the banks of the river bug, but there are no distant relatives, no humans, and apparently no life waiting for us on those other worlds. No letters conveyed by recent emigres help us to understand the new land, only digital data transmitted at the speed of light by unfeeling, precise, robot emissaries. They tell us that these new worlds are not much like home, but we continue to search for inhabitants. We can't help it. Life looks for life.
No one on Earth, not the richest among us, can afford the passage. So we can't pick-up and leave for Mars or Titan on a whim, because we're bored, or out of work, or drafted into the army, or oppressed, or because justly or unjustly we've been accused of a crime. There does not seem to be sufficient short term profit to motivate private industry. If we humans ever go to those worlds, then it will be because a nation, or consortium of them, believes it to be to its advantage, or to the advantage of the human species.
Just now, there are a great many new matters that are pressing in on us that compete for the money it takes to send people to other worlds. Should we solve those problems first, or are they a reason for going? Even if the call of the open road is muted in our time, a central element the human future lies far beyond the Earth.There may be small errors in this transcript.