A Review of the Feasibility of a Permanent Human Settlement on Mars

A review of current scientific literature, advocacy positions, and official statements reveals a complex picture regarding the feasibility of establishing a permanent human settlement on Mars. While space agencies and private companies have announced plans for crewed missions, significant obstacles remain regarding the planet's environment, human health, and governance.

Environmental Conditions on Mars

Atmosphere and Surface Pressure

Mars has an atmosphere approximately 1% as dense as Earth's, composed of 95-96% carbon dioxide. Surface air pressure is approximately six millibars.

Astrophysicist Dr. Jeffrey Bennett notes that increasing atmospheric pressure to levels compatible with human survival—requiring roughly 50% of Earth's atmospheric pressure—would require nearly 200 times the current pressure. Current estimates suggest insufficient carbon dioxide exists on Mars to achieve this density, limiting potential pressure to 7-12% of Earth's.

Temperature

Average surface temperatures on Mars are approximately -80°F (-62°C). Nighttime lows can fall below -125°F (-87°C). Temperature fluctuations of up to 100°F have been recorded.

Radiation

Mars lacks a global magnetic field and has a thin atmosphere, resulting in surface radiation levels approximately 50 times higher than on Earth. These conditions expose the surface to elevated cosmic and solar radiation.

Soil Composition

Martian regolith contains perchlorates, chemical compounds that can disrupt human thyroid function. The soil also contains oxidants and iron oxides. These substances present challenges for agriculture and require treatment before use for food cultivation.

Dust Storms

Global dust storms occur approximately every three Mars years (equivalent to 5.5 Earth years).

Human Health and Biological Considerations

Physiological Effects of Low Gravity

Mars' gravity is approximately 38% of Earth's. Astronauts in microgravity experience bone density loss of approximately 1-1.5% per month.

Extended exposure to Martian gravity may alter human physiology in ways that remain incompletely understood. Returning astronauts from lengthy space missions have reported fatigue, nausea, episodic blindness, premature aging, and impaired cognitive function.

Reproduction and Development

The effects of Martian gravity and radiation on pregnancy and fetal development are unknown. Biologist Scott Solomon, author of "Becoming Martian: How Living in Space Will Change Our Bodies and Minds," identifies reproduction in space as a significant ethical concern, noting the unknown safety of subjecting children to potentially hazardous conditions without guaranteed return to Earth.

Evolutionary Implications

Solomon suggests that human settlement across different celestial bodies could lead to evolutionary changes within relatively short timeframes—noticeable changes after four to five generations, with more significant changes after ten or more generations.

Psychological Challenges

Extended isolation, communication delays with Earth, and confinement within small habitats present psychological challenges. The "Earth-out-of-view" phenomenon, where Earth disappears from sight, could induce a sense of detachment. NASA has experimented with "veggie pods" to counteract psychological effects of monotony.

"We have co-evolved with our planet for four billion years."
— Nathalie A. Cabrol, astrobiologist

Habitat and Infrastructure Requirements

Necessary Systems

Viable human settlements would require continuous life-support systems for breathable air and climate control, extensive radiation shielding, closed-loop systems for water and food, and reliable energy sources. Multiple redundancies for all critical systems would be essential.

Radiation Protection

Dr. Jeffrey Bennett states that viable human settlements would likely need to be buried deep underground, within lava tubes, or protected by thick layers of Martian soil or advanced shielding materials.

Food Production

Agricultural challenges include the toxicity of Martian soil and the need for treatment before crop cultivation. Methods such as hydroponics or aeroponics with closed-loop water recycling systems may be required. Detoxifying soil at scale could require engineered microbes or fungi.

Advocacy and Official Statements

NASA and Government Positions

NASA announced plans in 2019 for a first manned mission to Mars in 2033. In January 2025, President Donald Trump stated his administration would "pursue our manifest destiny into the stars, launching American astronauts to plant the Stars and Stripes on the planet Mars."

SpaceX and Private Sector

The cost of launching objects into space has decreased from over $54,000 per kilogram in the 1980s to approximately $1,500 per kilogram, attributed to SpaceX's production and reusable launch modules.

In 2024, Elon Musk stated a timeline for Mars: "Less than 5 years for uncrewed, less than 10 to land people, maybe a city in 20 years, but for sure in 30, civilization secured." Two weeks prior to a January 2025 report, Musk posted that "the overriding priority is securing the future of civilization, and the Moon is faster."

Advocacy Organizations

Jerry Stone, a 71-year-old fellow of the British Interplanetary Society (BIS), stated that landing humans on Mars would be "a major step in the advancement of humanity." Robert Zubrin, aerospace engineer and president of The Mars Society, advocates for Mars settlement as a civilizational imperative, stating, "With luck, in my lifetime, I'll hear the cry of the first baby born on Mars."

Cautious Perspectives

Kelly Weinersmith, co-author of "A City on Mars," recommends a "wait-and-go-big" approach with an international research station on the Moon first, stating that reproduction and governance issues are under-examined.

Nathalie A. Cabrol, astrobiologist, noted that fewer than 700 people have been to space, providing a limited sample for understanding long-term effects.

"With luck, in my lifetime, I'll hear the cry of the first baby born on Mars."
— Robert Zubrin, The Mars Society

Governance and Legal Considerations

Current Treaties

The Outer Space Treaty (1967) designates space as an international commons but lacks enforcement mechanisms. The Artemis Accords (2020) include a clause allowing extraction of space resources, which some observers have warned could enable claims to territory.

Governance Concerns

Daniel Deudney, a political science professor, argues that Martian colonization could lead to geopolitical conflict and that the vulnerability of life support systems could enable totalitarian governance.

Historical Context and Fiction vs. Reality

Scientific Understanding

Interest in Mars began with Giovanni Schiaparelli's 1877 map of "canali," later misinterpreted as artificial canals by Percival Lowell. NASA's Mariner IV probe in 1965 revealed a barren surface.

Science Fiction Portrayals

Fictional depictions of Mars have evolved with scientific understanding but often lag in accuracy. Early works such as Edgar Rice Burroughs' "A Princess of Mars" (1912) featured inhabitants along canals. Kim Stanley Robinson's Mars trilogy (1992–96) explored terraforming, a process now considered less feasible without massive technological advances.

Science fiction often uses implausible devices, such as shields for radiation and artificial gravity, to circumvent complex realities.

Realistic Depictions

Some works have addressed physiological challenges: the film "The Space Between Us" (2017) depicted a boy born on Mars whose physiology adapted to lower gravity, making return to Earth life-threatening. H.G. Wells' "The War of the Worlds" (1898) highlighted immune system vulnerabilities that future colonists might face.

Key Takeaway

While prominent figures and organizations continue to advocate for Martian settlement, the scientific reality presents formidable challenges. From radiation exposure and low gravity to soil toxicity and psychological isolation, the path to a permanent human presence on Mars remains uncertain—though the drive to pursue it remains undiminished.