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The Habitability of Mars

Mars plant

Besides Earth, Mars is widely considered to be the most habitable planet in our solar system. It is extremely fortunate that we have a planet like Mars so close to us since, though it has often been depicted in popular culture as a threatening wasteland, the red planet is in fact an excellent candidate for settlement.

Here are some of the primary reasons why Mars is capable of hosting life (with help from human technology):

The Presence of Water
There is enough water on Mars (mostly trapped in ice) to cover the entire planet to a depth of 35 meters1. For instance, the Korolev crater located near Mars’ North pole holds a massive volume of water ice estimated at 1.8 kilometers in thickness2. This immense supply of water is crucial for exploration and settlement efforts since it can be used not only for drinking but also for the production of oxygen and hydrogen.

Mars Has an Atmosphere (and we can make breathable air from it)
Even though it is very sparse, Mars does have an atmosphere (primarily made of carbon dioxide). This is an important asset for humans-to-Mars because the carbon dioxide can be converted into oxygen and fuel using a relatively simple process. The NASA Perseverance rover scheduled to land on the red planet this month carries an experiment intended to demonstrate this conversion.

Essential Plant Nutrients
The soil on Mars contains many essential nutrients required for agriculture. The amount of nutrients varies according to geographical region, and the soil must first be remediated in order to remove toxic perchlorates, but the presence of these nutrients is an invaluable asset.

Raw Resources for Construction
Researchers have demonstrated that Martian soil (known as regolith) can be compressed into bricks for construction, without the need for additives. This is important because – if we can refine this process – the planet has a massive supply of readily accessible building material. Regolith can also be combined with sulfur (which is abundant on Mars) to produce concrete, and Iron can be extracted from regolith through a more energy-intensive process.

These are only a few examples of the numerous useful resources on Mars. To learn more about which resources are available, and how we can take advantage of them through a process called In-Situ Resource Utilization, read our series on ISRU.

Manageable Temperatures
Mars is very cold, with an average temperature of minus 62 celsius. As a result, human habitats will need to be designed with the ability to resist extreme cold. Fortunately, however, these temperatures are not beyond our ability to manage. In fact, there are cities on Earth that experience temperature as low as this.

Less Gravity
The red planet has 62.5% less gravity than Earth. It is unclear how this will impact the health of humans that spend long periods of time on Mars, however, research examining the health effects of astronauts who spent a consecutive year in space suggests that the human body is highly resilient to the spaceflight environment. With some gravity (37% that of Earth’s) it is logical to expect that astronauts on Mars would fare even better.

Recent research simulating human exposure to Mars gravity is already suggesting some promising countermeasures to possible physiological changes.

A Similar Day-Night Cycle
Earth and Mars have a very similar day-night cycle. A day on Mars is approximately 24 hours and 40 minutes. This is good news for human explorers and settlers to the red planet because our circadian rhythms are modulated by the duration of exposure to light. Living in an environment with almost the same length of day as Earth will be an important benefit to healthy sleep. A similar number of daylight hours might also be valuable for Martian agriculture.

The Challenge
Establishing a permanent human presence on Mars will require us to resolve a number of significant challenges. Perhaps chief among these is the presence of toxic perchlorates in the regolith. None of these problems are unsolvable. In fact, these challenges are practically insignificant relative to the sum of human innovation and creativity in recent history.

In less than two centuries, we have transitioned from burning oil lamps for light to electricity and nuclear power. In the same time frame, we have discovered antibiotics and plastics, learned to fly airplanes, and build computers.

Given the profound importance of establishing a multi-planetary future, it is difficult to imagine how we would not be able to resolve the difficulties before us on the path to Mars.

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The Mars Society of Canada offers a professional and credible platform for all space advocates to promote Canada’s participation in Mars science and exploration. By becoming a member of our federal not-for-profit, you provide direct support for our educational, public outreach and analog research efforts. We proudly represent the voice of thousands of Canadians who believe in the profound benefit of Mars exploration, and a multi-planetary future for humanity.

Written by Evan Plant-Weir, 2021