Are People Living on Mars? Percival Lowell, an American astronomer, thought he saw canals criss-crossing the deserts of Mars, when he observed the planet though his telescope early this century. He believed that these canals were built by a Martian civilization to bring water for irrigation from the planet’s polar caps. However, space probes have shown that the canals were simply optical illusions.
Mars is too hostile for any form of life due to the radiation, greatly reduced air pressure, and an atmosphere with only 0.16% oxygen. Human survival on Mars would require living in artificial Mars habitats with complex life-support systems. NASA is still aiming for human missions to Mars in the 2030s, though Earth independence could take decades longer. They laid out 2030 as the date of a crewed surface landing, and noted that planned 2020 Mars rover would support the human mission.
After all, humanity could be threatened with extinction due to some cataclysmic event; global warming, a deadlier pandemic, all-out war on Earth, or an asteroid strike. If we ever become—perhaps if we need to become—a multi-planet species, exactly how many settlers would be needed for survival on another planet? The answer, according to a paper published in Scientific Reports, is about 110 people.
The number of people that could be sent to another planet would be rather limited, says Jean-Marc Salotti at the Bordeaux Institut National Polytechnique, the author of “The Minimum Number of Settlers for Survival on Another Planet.” “A mathematical model can be used to determine the minimum number of settlers and the way of life for survival on another planet,” writes Salotti. “The minimum number of settlers has been calculated and the result is 110 individuals.”
That figure is interesting. SpaceX is currently working on its Starship, something of a reusable interplanetary spaceship that would be capable of sending 100 passengers at a time to Mars. However, Salotti has doubts about re-usability and thinks that developing a vehicle that can both land and relaunch from Mars could take several decades.
Concepts of crewed Mars missions take about six months for between three and six astronauts to reach the planet, along with a few dozens of tons of consumables. Although it may be possible for some resources to be obtained from Mars—carbon dioxide from the atmosphere, water ice from the soil to produce oxygen and organic compounds, hematite to produce iron, silicates to produce glass—we’re decades away from understanding if any of that would be practically possible.
Salotti’s calculations are based on the ability of a group of individuals to survive if cargo drops from Earth were stopped. That could perhaps be because a colony is becoming too expensive to send cargo to, because of war on Earth, or because the colonists decide to go it alone and declare an independent Martian republic.
It takes into account factors like how long the colonists would need to to spend mining, producing metal, ceramics and glass, chemicals and clothes, and recommends that colonists use three guiding principles:
Make it simple: minimize the need for complex objects. All individuals to live under a dome (covered in a few meters of soil to protect the colonists from radiation) and share the same life support system. Plants will be grown in greenhouses, water will be extracted from ice, solar panels use for electricity and methane used to power engines. Salotti thinks that producing new solar panels and new spacesuits would be a major challenge for the colonists that they would need to overcome.
Maximize sharing: everyone to share the dome’s ecosystem—air, water, food, energy, tools, spacesuits, vehicles and industries. This “sharing factor” would be critical, says Salotti.
Develop step-by-step: accept harsh living conditions in the short term, accumulate resources, create new bases and new industries in order to achieve a modern society after a few centuries.
“If this relatively low number is confirmed, survival on another planet might be easier than expected,” writes Salotti.
Content for this question contributed by Jamie Carter (Senior Contributor), forbes.com(science)
