As ever-deepening turmoil engulfs Earth, daydreaming about moving to Mars might provide a pleasant break from our everyday predicaments. It is entirely understandable—and human—to grasp onto promises of a better life in a faraway place. But when Martian daydreams, in particular, turn into reality, the picture becomes less pleasant. What promise could a barren, hostile planet like Mars hold? As far as the solar system is concerned, we already inhabit a paradise.
Nevertheless, Mars is on the menu. NASA’s proposed Artemis mission ends with people planting flags on Martian soil in coming decades. China plans a sample return mission to Mars, and India plans to send another orbiter there in 2024. Even Earth’s newest space billionaire, Elon Musk, has joked about spending his last years on Mars, apparently intending to make humans a multiplanetary species.
The wildest plans for Mars—at the far edges of plausibility—include settling a million people permanently on another planet. Such an endeavor, like any mission that involves sending people to outer space, would be extremely risky and expensive. Some visions to take a large group of humans to stay permanently on the Martian surface would require rockets transporting 100 metric tons of cargo or 150 passengers at a time to land directly onto the Martian surface. To reach a million inhabitants of the Red Planet within a century would require approximately 7,000 passenger ship trips as well as more than 50,000 food cargo flights (not to mention the transport flights for the machinery, components and other materials), feasible only during the launch window that opens every two years. Even with this excessive expenditure, life would remain very restricted and risky for Mars immigrants. Thus, you’d need a very good justification for this kind of large-scale settlement. After all, it is not merely an engineering challenge but also an ethical one.
The rapidly growing space ethics literature discusses several reasons for space expansionism, for example, new scientific knowledge and discovery, long-term survival of humanity, economic benefits, inspiration and adventure. Do any of these justify the costs, risks and dangers involved in establishing a permanent Martian settlement? Frankly, no. While most of them fail for various grounds, the only shoe that fits is too weak to justify such an enterprise.
Studying Mars IRL may reveal important scientific discoveries, such as extinct or extant life on Mars. Thus, science provides a great reason to go to Mars—just not for a permanent settlement. A smaller outpost would be enough for most scientific inquiry. Furthermore, larger-scale settlement activities directly conflict with some scientific goals. Large human populations, through habitation and excavation, could contaminate the objects of studies and interfere with research.
At face value, the long-term survival of humanity seems to provide a solid and noble cause for building permanent settlements on Mars. However, for a Mars settlement to truly mitigate extinction risks it must be adequately self-sufficient. This is unlikely to be achieved any time soon, and we may not have the time to wait. Instead, investments in global food security, meteor or comet deflection, pandemic preparedness and global peace appear far more cost-effective than building a settlement off-world. Additionally, some risks may follow us to Mars , such as rogue artificial intelligence, meaning that a settlement on Mars does not lower the total risk of extinction that much. Therefore, while in the long term safeguarding humanity may provide a good reason to settle other planets, it does not give us an urgent one.
The economic promise of Mars also seems tempting, but it may prove to be specious. For now, interplanetary travel and operating in deep space are just too expensive. Most economic opportunities are better cashed out closer to Earth. For example, it is likely far more cost-effective to mine the moon or near-earth asteroids rather than Mars or the asteroid belt. The same probably applies to tourism or space manufacturing. Moreover, industries on Mars may jeopardize scientific goals. Hence, if we want both scientific and economic benefits of Mars, the science should come first and business later.
Settling Mars could also provide inspiration for both settlers and the large majority safe on Earth. Even so, it is not clear that it would be inspirational enough to be worth it. One can of course tell fanciful stories about how settling Mars helps us avoid societal stagnation and provide new spiritual insights and fruitful political and philosophical ideas, but it sounds a lot like wishful thinking or an act of faith. Also, the sheer achievement of going to Mars could prove inspiring, but it is not clear that we need a million people there for that kind of inspiration; the first four or so pairs of boots on Mars would likely do the trick. Looking to the moon landings, the first ones captured great attention, but subsequent Apollo mission interest soon faded, with daily quiz shows garnering higher ratings. The same could happen with Mars.
Finally, one obvious reason for going to Mars is the sheer adventure of it. Indeed, extraordinary adventure and thrills would await those brave individuals who settle Mars. And unlike the other reasons, adventure does not become redundant after a certain point. There can always be more adventure for more people, while the other reasons can be fulfilled with less risky and expensive endeavors like a small science outpost. This makes adventure in one sense the strongest reason for establishing a million-person society on Mars. Of course, it is appropriate to question whether the gargantuan effort of building a permanent settlement on the Red Planet can be justified by such a frivolous reason as adventure. In this sense, the strongest reason for settling Mars is also the weakest.
We can pursue the other goals with far less risk and expense than a Mars settlement entails. NASA has produced multiple small exploration mission designs. None have been pursued, in light of the high cost of safely sending humans to Mars. However, crewed missions, and maybe a station either in Mars orbit or the surface, are again being planned to continue the Artemis program. At the forefront of current space technology, that is far more realistic than sending a million people to Mars.
Dreaming about Mars can be valuable and has sparked discussion and research in many fields. Yet, perhaps for the time being it should remain only a dream.
This is an opinion and analysis article, and the views expressed by the author or authors are not necessarily those of Scientific American.