There is No Planet B

Can Space Travel Rescue Humanity from a Troubled World?

Many astronomers were first inspired by human space exploration programs, including the Apollo Missions, the Space Shuttles, the International Space Station, and more recent efforts by NASA, SpaceX and Blue Origin to make inter-planetary travel a reality.

Furthermore, many science fiction books and films—which inspire us all—are motivated by real discoveries made by astronomers, engineers and space scientists making use of space missions and observatories such as the Hubble Space Telescope and the Kepler Exoplanet Mission.

Given these imagined marvels of Sci-Fi—and the real world marvels that are accomplished and uncovered daily—we are constantly invited to ponder a universe of infinite possibilities. But, when it comes to the imminent fate of our species, we are obliged to be pragmatic.

We would like to take a moment to clear up a misconception that our own research (and the excitement that surrounds it) has created: the notion that transporting people from Earth to destinations in space might be a viable way to cope with a degraded ecology on Earth. This is not possible in the immediate future for the following reasons:

Daughter of the Stars, 2020. D. Stein & S.N. Virani.
Daughter of the Stars, 2020. D. Stein & S.N. Virani.
ESO, N. Bartmann, spaceengine.org
ESO, N. Bartmann

Thousands of planets outside our solar system have been discovered, and a handful of these are now thought to be habitable, i.e., capable of sustaining conditions such as liquid water that life on Earth requires. However, the distances to these planets make it impossible to consider space journeys to any of them in a reasonable time. Travel time to even the nearest known exoplanet would take hundreds of years with current technology. And (sadly), we do not know how to travel faster than the speed of light. As this video shows, such an experiment would violate causality, creating a paradox in which the future affects the past.

If we ever become capable of landing humans on a habitable exoplanet there will be many moral dilemmas. If life already exists on that planet, could we safely coexist? Would we want to displace or destroy that life? Will we become the science fiction monsters that we fear on Earth?

Exploration of our solar system by robotic space probes in recent decades has captured the excitement of scientists and the public. The prospect of human outposts on other planets seems like it may be just around the corner, as portrayed in movies like “The Martian”.

But setting up a habitat for hundreds of people is a far cry from creating a new home for some 7 billion people. Settlements for many people on Mars would require terraforming of the planet by delivering greenhouse gases. We only have to look at the atmosphere of our home planet to see that such alterations are possible. However, the process of terraforming Mars would take thousands of years and might not be stable. Our species evolved on Earth. It is a much easier task to manage our own planet.

The energy required to lift all humans off the Earth is enormous. Simple calculations show that the total energy expenditure required to launch all of humanity into space exceeds all of the remaining fossil fuel on Earth. Someone will need to decide who will be abandoned on a dying planet.

Of course, we could just use a different fuel: nuclear fusion reactors, or enormous solar panel arrays. But if we succeeded with this alternative fuel plan, then we wouldn’t need to leave Earth in the first place! It is far easier to solve the problems causing the climate crisis on Earth than to try to move the bulk of humanity to another planet.

Science fiction books and films contain dramatic narratives to make them exciting. Either the setting is post-apocalyptic and hopeless, or some miracle occurs. Real problems are solved by real people who are willing to roll up their sleeves and put in serious work. The climate crisis is a solvable problem that has only gotten worse because it is not being addressed.

Solving the climate crisis will have an added benefit: it will unite humanity as we work together altruistically.