Another giant leap
Space travel has reentered public consciousness after the recent endeavours of billionaires Jeff Bezos and Richard Branson who have both undergone their first private voyages to the edge of Earth’s atmosphere in the last six months.
Although there’s plenty of controversy about these flights of fancy, especially concerning the irresponsibility of their massive carbon emissions, it does reopen the books on humanity’s relationship with the great beyond and, specifically, our nearest planetary neighbour: Mars.
Alongside the existing automated explorers that are currently charting the red planet’s surface, there are several international efforts underway to get human beings walking those crimson sands as soon as possible.
NASA is under presidential order to land people on Mars by 2033, the United Arab Emirates has announced a 100-year colonisation plan, and Elon Musk of SpaceX has projected a comprehensive two-phase mission that could have boots on the ground as early as 2026.
But since so much of human habitation depends on plants, food and oxygen most crucially, the big question is what could we grow there?
Extraterrestrial horticulture
The limits of what plants could survive on Mars are intimately linked to the environmental conditions of the planet and how vastly they differ from those we find on Earth.
The Villanova Mars Garden Project, headed by Dr Edward Guinan – a professor of Planetary Science and Astrophysics – aimed to replicate the Martian surface as closely as possible and test which plants might survive and thrive in its Iron Oxide-rich soil.
Guinan has already been instrumental in our understanding of Mars’ biological potential as he collaborated with the team that discovered the planet’s large frozen water deposits in 2022.
“Because Mars has sunlight and lots of permafrost, it has the capability to be terraformed — that is, made earthlike to support life in specific regions…”
-Dr. Edward Guinan
The plants that Guinan and his students selected, The Villanova project is based out of a Philadelphia university campus, included lettuce, onions, garlic, and sweet potatoes.
The first challenge that the team encountered was that their first major challenge, Martian soil, aka Regolith, has an especially clay-rich composition and is nearly impossible for tender roots to penetrate.
This means that any planting efforts on Mars would either have to focus on varieties with hardier roots or have a site dedicated to filtering and recomposing soil to have a looser structure.
Looking to Lichen
Another recent experiment in theoretical xeno-horticulture was based around a species of Lichen found in the frozen wastes of Antarctica.
The study was conducted in 2014 by an international team representing the Berlin Institute of Planetary Research and Washington State University. As one of the driest and coldest places on Earth, Antarctica makes for one of the best analogues of Mars’ living conditions that we can find here at home.
Moreover, Antarctica is also bombarded by one of the highest concentrations of UltraViolet radiation found anywhere on the planet – due to Mars thin atmosphere, a lack of protection from the suns rays would be of paramount concern to any would-be colonists.
As such, the native flora of Antarctica represents some of the strongest candidates with which to seed Mars and among them is the Gold Cobblestone Lichen.
The team constructed an artificial proxy of the Martian environment with low atmospheric pressure, temperatures, and water levels as well as high CO2 content to test how the Lichen might perform.
Remarkably, although Lichen on the ‘surface’ stopped growing, the samples placed in the crags of rocks – where they were growing in Antarctica in the first place – were able to continue photosynthesizing and
grew for the remaining 34 days of the experiment.
While this isn’t definitive proof that the Gold Cobblestone is ‘Mars ready’ it does give us hope that we may not be as far away as we think from building a Martian oasis.
