How to live on Mars?

Scientists have determined the conditions needed to warm Mars enough for plants to grow.

In the latest research presented by the Space Research Association (USRA) at the Astrobiology and the Future of Life conference held on October 18, scientists have proposed atmospheric conditions that would allow plants to grow on Mars .

Illustration depicting the Mars terraforming process. (Photo: Daein Ballard).

Research shows that increasing carbon dioxide (CO ₂ ) concentrations in the Martian atmosphere were crucial to raising the planet's temperature, creating conditions for plant growth.

The hypothesis of growing plants on Mars was put forward by Robert Olszewski, a professor at the Warsaw University of Technology in Poland. He and his colleagues looked at the surface energy balance on Mars, specifically the heat exchange between the condensation and evaporation of CO ₂ gas .

What's remarkable is that the conditions favorable for plant growth on the Red Planet are concentrated in regions other than the 'tropics' that researchers often think of.

'Surprisingly, the conditions that allowed plant growth did not first appear in the tropics (around 25°C) but in the Hellas basin. Further increases in the greenhouse effect would have expanded the area suitable for plant growth ,' the study explains.

Heat map of the tropical region (±25°C) on Mars. The Hellas Basin (marked) will be the first place to grow plants. (Image: Olszewski/MOLA).

Using some of the temperature and pressure data collected by the Viking Mars lander in the 1970s, Olszewski and his colleagues simulated various processes occurring on Mars, both past and present, and in the future.

Olszewski and colleagues assessed the total pressure required on Mars, the acceptable CO ₂ percentage , the amount of O ₂ required, the amount of water available, and the temperature range needed for plant growth to colonize the planet.

Of these, temperature is the most important factor when we want to transform a planet. Temperature directly affects the amount of CO2 _and the ability to form water.

" Mars' temperatures would need to be several tens of degrees Celsius higher, while the temperature swings between day and night would need to be much lower. For plants to grow, the growing season would have to last at least 110 days on the planet , " the study found.

Additionally, Olszewski and colleagues point out that on Earth, the highest tree densities are found primarily in the tropics — but are modulated by the location of the thermal equator.

"Therefore, it can be predicted that the equatorial regions of Mars would be where the first trees appeared ," the scientist said.

However, due to the large eccentricity of Mars' orbit, the southern hemisphere experiences warmer summers when the planet is at perihelion. Additionally, one year on the Red Planet is equivalent to about 1.9 Earth years.

'Therefore, the long summer in the Southern Hemisphere provides a suitable first growing season for trees. In particular, we found that the Hellas Basin had the most favourable first conditions ,' the researchers concluded.