Mars is unique among extraterrestrial bodies in that it already has the raw materials necessary to support human civilization. We can best understand Mars’ uniqueness by comparing it with the Earth’s Moon; the most frequently cited alternative location for extraterrestrial human settlement. The only remaining issue would be establishing an international space law to govern the disbursement of those resources.
How does Mars compare to the Moon?
The Martian surface is rich in carbon, nitrogen, hydrogen, and oxygen in biologically accessible forms, such as carbon dioxide gas, nitrogen gas, water ice, and permafrost. Carbon, nitrogen, and hydrogen are all present on the Moon in parts per million quantities, similar to gold in seawater. The Moon has abundant oxygen but only in tightly bound oxides such as silicon dioxide, ferrous oxide, magnesium oxide, and aluminum oxide, which require extremely high temperatures to reduce.
Scientists already know that if Mars were to be smooth and its ice were to suddenly melt, the whole planet would be buried by an ocean that would be more than 100 meters deep. The same cannot be said about the lunar surface – which is considerably dry. Colonists there would have to literally mine for water.
Deficiencies on the Moon
Mars contains all the elements in abundance. About half of the metals of interest to industrial society are also deficient on the Moon (copper, for example) and many other elements of interest, such as sulfur and phosphorus. Furthermore, hydrologic and volcanic processes on Mars, as on Earth, likely resulted in local concentrations of high-grade mineral ore formation.
Mars’ geological history has been compared to Africa’s, with very optimistic inferences of its mineral wealth. However, the Moon has never seen water or volcanic activity, so it is made up of trash rocks with little differentiation into ores that can represent proper concentrations of minerals.
Power availability
Solar panels can be used on either the Moon or Mars. Here, the Moon’s clearer skies and closer proximity to the Sun roughly balance the disadvantage of the lunar cycle’s large energy storage requirements. Suppose you are looking to create a self-expanding power base. In that case, Mars has an enormous advantage since it possesses large quantities of carbon and hydrogen needed to produce the required pure silicon for making photovoltaic panels and other electronics.
Mars also can generate wind power, whereas the Moon does not. The power potential of solar and wind is relatively modest – tens, or at most hundreds, of kilowatts at most.
You need a powerful energy source to build a vibrant civilization. In the short- and long-term, Mars has both in the form of its geothermal energy resources, which offer the potential for large numbers of locally created power plants in the 10 MW (10,000 kilowatts) range.
Over the long-term, Mars could have a power-rich economy because of its ample supply of deuterium fuel for any type of fusion reactor. Deuterium is roughly five times more common on the planet Mars than on Earth, and over tens of thousands of times more common there than the Moon.
The rich minerals om outer space are in abundant supply to the point that comprehensive space law is needed to govern its claim.
Problems with crops
Nevertheless, the biggest problem with the Moon, as with all other airless planets and artificial free-space colonies, is that sunlight does not reach the Moon in a form that can be useful for growing crops. A single acre of plants requires four megawatts of sunlight power; a square kilometer needs 1,000 MW.
The entire world combined cannot produce enough electrical power to illuminate the farms of Rhode Island, that agricultural giant. Using electrically generated light to grow crops is just uneconomic.
On the Moon, you cannot use natural sunlight without building thick greenhouse walls that shield out solar flares, an expense that would increase cropland creation enormously. Even if you did that, it wouldn’t help you because on the Moon plants cannot grow in a light and dark cycle that lasts 28 days.
The Martian atmosphere is thick enough to protect any crops from solar flares. Thus, UV-resistant hard-plastic shield domes protected by thin-walled inflatable plastic greenhouses can be used to create cropland on the surface quickly. Even without the solar flare issue and the month-long diurnal cycle, such conservatories would be impractical on the Moon because the temperatures would be unbearably high.
Domes up to 50 meters in diameter are light enough to be transported to Mars from Earth initially and can be manufactured from local materials on Mars later. Having all the resources to make plastic on Mars, such 50- to 100-meter domes could be deployed rapidly, causing large surface areas suitable for both human habitation and agriculture. Such crowns would produce a temperate climate inside Mars because they create a strong greenhouse effect.
Human beings will eventually have the capacity to significantly thicken Mars’ atmosphere by forcing the regolith to outgas its contents through a deliberate program of artificially induced global warming. After this is accomplished, the domes would be of virtually any size since they would not have to endure a pressure differential between their interior and exterior. Once this is done, it will be possible to grow crops outside the domes.
Final thoughts
Contrary to colonists on any known extraterrestrial body, Martian colonists will be able to live on the surface, not in tunnels, and will be able to move freely and grow crops in the daylight. Mars is a place where humans can flourish and grow in large numbers, making products of all kinds with indigenous materials. It is thus possible to develop civilization on Mars, rather than just a mining or scientific outpost. Additionally, Mars and Earth are the only two planets in the solar system where humans will be able to grow crops for export.
