Visions of apocalypse and dystopia fill popular fiction and film and, these days, even the imaginations of many serious people.
Geniuses including Stephen Hawking and Elon Musk have called for an escape from the planet. Billionaires are said to be preparing bunkers and remote fortresses.
It’s easy to see why, even if you aren’t worried about our new president having an itchy trigger finger on the nuclear button. Climate change projections of rising temperatures, extreme weather events, and violent conflict all seem to be arriving on schedule.
If things go really bad on planet Earth, could we send people to live on another planet and save the human race?
NASA depicts livable conditions in artist renditions of newly discovered Earth-sized exoplanets circling other stars. Musk promises to send space tourists on a joyride around the moon. How far away could it be before people land and stay?
In a new book co-authored with Dr. Amanda Hendrix, Beyond Earth, we’ve studied plans for space colonization both seriously and skeptically. And we do believe pioneers will eventually leave and make new homes in space.
But that journey will be no substitute for solving Earth’s problems. Indeed, solving problems here on Earth may be a prerequisite to settling in space.
It is much harder for human beings to get to another planet and settle there than many people seem to think. The can-do attitude of space boosters is part of the problem.
Underselling the challenges has produced unrealistic expectations about our abilities and weakened our efforts to overcome them. Lacking sustained investment or a long-term vision for human space exploration supported by the public, no human being has gone beyond low Earth orbit since Apollo 17, in 1972.
Musk and other commercial space entrepreneurs have accomplished amazing technical feats, but they also have the bad habit of overpromising. Musk’s SpaceX accepted a deposit for the moon orbit before he has orbited people around Earth.
He may well succeed. China may put crews on the moon within 20 years. But these goals aren’t in the same league as going beyond the moon. And landing to stay is even further off. At the current pace of investment, a space colony will never happen.
Space radiation and the neurological hazards of weightlessness put destinations other than the moon out of reach with current technology. The risk to passengers is too high. We need significantly faster spacecraft and a much better understanding of the health hazards of space travel.
NASA has embarked on these studies, but answers may take decades.
Even with a safe mode of travel, moving many people to another planet would cost an enormous amount, far more than the passengers themselves could afford. No one has identified a space resource that would compensate for that investment, so altruistic Earthlings left behind would have to pay the bill.
If the world falls apart, how willing would they be? A mission to send a few astronauts to Mars for a brief visit could cost a trillion dollars. Would nations struggling with climate disasters, wars, and mass migration pay that much—and far more—to dispatch and support a group of colonists?
On Earth, governments often launched colonial ventures that would become self-supporting and profitable. The Lost Colony of Roanoke Island, in North Carolina, is an example of one that didn’t, and perished.
The colony’s disappearance is relevant. Queen Elizabeth I sanctioned it, but when the Spanish Armada attacked England in 1588, she refused to spare ships for resupply. A modern leader faced by world war might make a similar choice if faced with the expense of supporting a space colony.
Scant opportunities for a self-sustaining space colony exist in our celestial neighborhood.
No place in our solar system is as hospitable to life as Earth’s least hospitable place. Human beings on Mars would have to live underground for shelter from radiation. Creating a protective atmosphere on Mars would take many lifetimes.
We do not currently know how to build a self-contained, self-sustaining underground habitat on another planet.
An Earthlike exoplanet circling another star could have an atmosphere, and perhaps even oxygen and life. NASA has discovered enough new planets to create confidence that they are ubiquitous in the galaxy. Sheer chance promises some should harbor pleasant human habitats.
But we know little about conditions on particular exoplanets. In February, NASA released lovely landscapes imagined of the seven new planets around the star Trappist-1. Unfortunately, the artist’s imagination was the most impressive aspect of the pictures. All scientists can really tell us about them is their size and the radius of their orbits.
Soon, new instruments may tell us much more, including the presence and composition of the planets’ potential atmospheres. But these planets are so far away that getting there would take something like a Star Trek warp dive.
In Beyond Earth, my co-author and I solved these puzzles by proposing a destination where colonists could support themselves on the surface with technology not much beyond our current capabilities. Our destination is Titan, a moon of Saturn with a thick nitrogen atmosphere and essentially limitless supplies of energy and water.
Getting there safely would require building fast propulsion that has only just been conceived of, but not something beyond imagination. We can live on Titan and we will eventually be able to get there. But we won’t be able to do it for a long time.
How long it takes depends on unpredictable technology development. We’re highly unlikely to live to see our Titan settlement founded.
Saving this planet will have to come before sending a colony to space. That’s good, because the task will be infinitely easier. We already have the technology to transform the energy industry. A strong response to climate change could spawn an economic boom.
That’s just what space exploration needs. A healthy, growing economy can power the rapid innovation that produces transformative technology—such as the technology for a space colony—as smart people and companies compete in an environment of wealth.
Cold War conflict drove competition to land on the moon. But that rich battle of prestige was much different from the conflict the doomsayers envision. A world descending into chaos due to climate stress and religious war would not dedicate itself to such a triumph.
Humanity is stuck with this planet for a long while yet, for good or bad. There will be no lifeboat. But we’re OK with that. We would prefer to reach into space as an expression of hope rather than fear.
Charles Wohlforth is author, with Dr. Amanda Hendrix, of Beyond Earth: Our Path to a New Home in the Planets, published in November by Pantheon.