Beyond climate change, there are more dangers to the long-term survival of our species. Physicist Stephen Hawking had said we have about a thousand years left on Earth, and he later revised that number to one hundred years. Hawking cites climate change and overpopulation as major threats, as well as the development of powerful technologies, especially artificial intelligence (AI), that may incite catastrophic wars, either using AI against each other for control of the planet or wars against AI. Stephen Petranek has developed a list of some ten ways our world might end suddenly, among them a planet-killing asteroid, which would strike Earth with the force of many Hiroshimas and raise a dust cloud blotting out the sun that would kill all the plants on Earth that life depends on. Like the dinosaurs, we would not escape such an event, and such an event is a statistical inevitability. It’s just something that happens from time to time, and as of yet we have no defense against it. As Carl Sagan has written, human beings have but two choices: “spaceflight or extinction.”
Elon Musk too “is keenly aware that Earth will not be habitable forever,” writes Petranek in How We’ll Live on Mars. “Musk seems frustrated by our denial about what we are doing to our habitat [the Earth], and is ever cognizant of a simple fact: humans will become extinct if we do not reach beyond Earth.” And reaching beyond Earth means colonizing Mars. It is the only option now, maybe the only option ever. The runaway greenhouse effect on Venus makes it far too hot (some 900 degrees Fahrenheit on the surface), and the moons of Saturn and Jupiter are too far away, at least for our initial effort. At about a six-month journey one-way, Mars is not much farther off than Lisbon was from Rio de Janeiro in the sixteenth century. While conditions on Mars make it challenging, it is achievable. Establishing a colony there will be, writes Petranek, “nothing less than an insurance policy for humanity.” Or as Musk has put it, a backup for the biosphere.
The first two decades of the twenty-first century have been a boon to space science and exploration. We—the human animal—have landed the rover, Curiosity, on Mars to explore the Gale Crater and environs (2012); landed the Philea probe on the comet 67P/Churyumov-Gerasimenko (2014); discovered that liquid water flows on Mars, making it ever more likely that life was or still is present there (2015); flew the New Horizon probe past Pluto to explore that astonishing and active world at the limit of our solar system (2015); inserted the Juno probe into orbit around Jupiter to find out more about that planet’s formation and origin, and thus the formation and origin of Earth (2016); detected gravitational waves pulsing outward from the collision of two massive black holes at an immense distance from the Earth, waves that Einstein’s theory of general relativity predicted a hundred years ago (2016); discovered that Earth has a second moon, a little asteroid called 2016 HO3, that our planet caught about a hundred years ago and will likely hang on to for a couple hundred more (2016). We accomplished all this using robotic technology. No one had to travel to the moon, and no one had to travel to Mars.
When I began to explore Laika’s story, I felt strongly that human beings should not go to Mars. We should stay put and work on things at home, because the fate of humanity is inseparable from the fate of the Earth. We should use our capital, ingenuity, intelligence, and cooperative spirit to build a more sustainable civilization here on Earth, one that will stabilize and then reduce human population growth, repair our decimated ecosystems, and encourage biological diversity. Humans will do better, because the Earth will do better. When I began to explore Laika’s story, I wanted to make a plea for an expansion of robotic exploration of our solar system and an end to crewed missions into space. Robots are cheaper and hardier than humans, and they don’t require training or life-support systems. Instead of the expense and resources required to send humans to Mars or anywhere else, we should send robots and robots alone, robots that are, as Carl Sagan has written of his beloved Voyager spacecraft, “intelligent being[s]—part robot, part human,” that “[extend] the human senses to far-off worlds.” Without humans in space, we might also reduce the need for biological research in space. We would not need to learn how to survive long-term in microgravity or how to shield ourselves from deadly radiation in space or on Mars, and we would no longer need to send animals of any kind into space. If biological research did continue in space, it would be directed away from how humans might live out there and toward how humans and all Earth’s creatures can live better here. That research would help us take care of our planet, not help us leave it. When I began to explore Laika’s story, I wanted to say that space exploration is already at its limit, that Mars is a fantasy and will always remain one. The dream of Mars, I wanted to say, is no better than a wish for immortality, a wish for what we can never have. I wanted to say that what we really need as a species is to stay home, on Earth. What we really need is to be at home on Earth.
But I feel differently now.
Freeman Dyson is right—he must be right—that the human animal needs, always, a new frontier to push against. We cannot prosper without the exercise of our spirit of discovery and exploration. We need to explore to remain whole—physically, emotionally, psychologically. Maybe even spiritually. Going to Mars is not for everyone, but everyone will be struck with awe and amazement when we do. Nothing good will come of a suppression of human desire. It will manifest itself, either in a positive way that unites us and inspires and improves life on Earth, or in a destructive way that continues to polarize nations, fuel bloody competition for resources, and ensure the end of us all. Restraint is not the way. The way is expression, release, liberty, Mars.
When I spoke to astronaut Donald Pettit, I asked him what he thought about a crewed mission to Mars, about establishing a permanent colony there. Is Mars even possible? “It’s inevitable,” he said. “Human beings will become scattered throughout the solar system.” At the present rate of development and planning, he said, it will take a couple hundred years but we can easily accelerate this process if we have the financial and political will.
Having come this far, having gone that far out, how can we turn our back on human space exploration, on the adventure that is Mars, when such adventures have the power to free us from our myopic and self-serving perceptions? How can we turn our back when such an adventure may bring us to understand again that we are in the universe together, and it is our togetherness—our empathy for all living creatures—that sustains us? Instead of squabbling and warring on Earth, all of humanity might join in the project to colonize Mars. How can we turn our back on Mars when, as Hubert Planel writes in Space and Life, “exploring faraway hospitable planets directly has always been Man’s dream”?
John Karas, vice president of business development at Lockheed Martin, believes it will require a cooperative effort to colonize Mars. “Space is a matter of national pride,” he said. “Nations want to be in space because it is the technological high ground. But I don’t see a Space Race today so much as a space cooperation, or collaboration. Likely Mars will be a joint venture among a consortium of nations. We can’t do it alone. To go to Mars, we will need to collaborate with spacefaring nations. This will be a human endeavor, not an American or a Russian endeavor.”