Although it’s little more than a barren wasteland nowadays, our planetary neighbor Mars is similar in many ways to Earth. Its length of day, dry surface area, and general relief are similar to those on Earth, which makes the Red Planet a prime target for an eventual colonization attempt.
But if we want to set up a permanent settlement on this telluric planet, there are many challenges we need to overcome — one of them, the sustainable cultivation of edible crops, has just made a revolutionary leap forward.
In a recently published paper, researchers John G. MacDonald, Karien Rodriguez and Stephen Quirk developed an oxygen delivery polymer that enabled the first successful germination in a Mars-like environment.
From seed to seedling
On Mars, there already are already some resources that we can use to grow harvestable plants. For instance, the layer of loose, soil-like material called regolith contains chemical elements such as phosphorous, iron, and potassium — all of which are needed for most plants to grow. However, until now, it has not been possible to successfully germinate plants conditions such as those on Mars.
The problem — or at least, part of the problem — is oxygen.
While plants are able to supply their own oxygen after some time, it is needed in molecular form for most plants to develop from seed to seedling. Unfortunately, the Martian atmosphere consisting of 95% carbon dioxide, contains mere traces of oxygen.
While there are types of plants capable of anoxic germination (most noticeably rice) this adaptation comes with some major drawbacks like a reduction of cellular respiration which is why they have to rely on the little efficient fermentation as an energy source.
Molecular oxygen is also needed for the redox reactions that produce generating reactive oxygen species (ROS) with essential signaling functions.
There are two ways of obtaining oxygen in a Mars-like environment: extract it from regolith metal oxides, and electrolysis. Both have some major downsides, namely time consumption and proximity to water respectively.
In a recent paper, scientists propose a different approach: they developed a polymer system. When combined with sodium hydroxide and hydrogen peroxide, the polymer becomes an oxygen infused foamed hydrogel which can deliver controlled amounts of gaseous oxygen. The foamed matrix can be mixed into the regolith or coated around the seed and can be used to grow plants.
In other words, for the first time in history, scientists succeeded in germinating plants in a martian environment. Cress, a typical test object for plant research, grew almost identically in the uninviting environment when the polymer system was used in comparison to the control group.
The findings of the scientists from Georgia, US, could mean a big step forward towards the distant possibility of a human colony on Mars.