While Elon Musk’s goal of settling Mars within the next 30 years has sparked excitement about humanity’s future as a multiplanetary species, a new book casts serious doubts on the feasibility of such a vision. In A City on Mars: Can We Settle Space, Should We Settle Space, and Have We Really Thought This Through?, authors Kelly and Zach Weinersmith argue that settling the red planet is far more challenging—and dangerous—than many realize.
The Weinersmiths, a biologist and a cartoonist, explore the myriad obstacles humans would face in establishing a sustainable presence on Mars, from environmental dangers to the complexities of human reproduction. Their research, which led to their skepticism about space colonization, earned their book the 2024 Royal Society Trivedi Science Book Prize.
Initially intrigued by the possibility of space settlements, the authors delved into the harsh realities of Martian living. Kelly Weinersmith explains, “We were pretty excited about space settlement happening… but the more we got into it, we realized there’s a lot we don’t know—and doing this too soon could lead to an ethical catastrophe.”
The Harsh Reality of Mars
The book argues that the idea of leaving Earth for Mars is akin to escaping a messy room only to end up in a toxic waste dump. The Martian environment, with its weak gravity, extreme radiation, thin atmosphere, and toxic soil, poses significant threats to human life. “Mars just lacks a lot of the stuff that we have on Earth,” says Zach Weinersmith, noting the planet’s hostile conditions, including a 40% gravity compared to Earth, high radiation levels, and perchlorate-laden soil, which could disrupt human health and development.
The authors are particularly concerned about human reproduction on Mars. With limited data on how humans will respond to Mars’ conditions, the risks for pregnant women and babies could be catastrophic. Studies from space stations suggest that microgravity weakens bones and muscles, which would worsen on Mars, where gravity is only 38% of Earth’s. Kelly Weinersmith points out that even a slight bone loss could prove fatal during childbirth, emphasizing the need for more research into reproduction in space.
Slow, Steady Progress for Research
While the Weinersmiths are not dismissive of space exploration, they argue that short-term colonization is impractical. Instead, they see potential for incremental progress, such as setting up research stations on the Moon and conducting experiments on animal life in space. The authors predict that in the near term, humans may land on Mars, conduct scientific exploration, and return to Earth, but permanent settlements and reproduction will remain out of reach for now.
The biggest challenges lie in sustaining life on Mars. Technologies to build space farms, establish safe habitats, and produce oxygen in closed-loop systems are still underdeveloped. “We don’t really know how to do that,” says Zach Weinersmith, highlighting the immense research needed for survival in such a sealed, extreme environment.
Ethical and Geopolitical Concerns
The Weinersmiths also raise significant ethical and geopolitical issues. The Outer Space Treaty of 1967, which governs activities in space, provides little guidance on issues like resource extraction and territorial claims on Mars. This ambiguity could lead to international tensions, particularly between space powers like the United States and China, as they race to control valuable sites on Mars and other celestial bodies.
A Reality Check on Space Settlements
Ultimately, A City on Mars presents a cautionary tale about the complexities of interplanetary settlement. While space exploration holds tremendous potential for scientific advancement, the authors argue that the dream of colonizing Mars in the immediate future is a dangerous and unrealistic venture. Their book calls for a more measured approach, emphasizing research, ethical considerations, and long-term planning over the rush to claim Mars as humanity’s second home.
