There is a good chance we will be on track to colonise Mars by 2050. While we’re currently yet to set foot on the Red Planet, there are many national and private entities looking to send people to start new lives on our closest neighbor.
However, colonising Mars won’t be easy. One of the biggest problems is the lack of arable land for growing food. A colony-sized landing party would require a sustainable food source once their initial reserves run out, and currently it would be all but impossible to grow food on Mars.
The surface of Mars is barren, made of a thick layer of oxidised iron dust and rock, making it impossible to grow plants in the traditional way we’re used to back on Earth. However, the soil does also contain sodium, potassium, chloride, and magnesium, some of which can aid plant growth.
To make things worse, the core of Mars doesn’t move, and therefore doesn’t have a magnetic field. This means the planet struggles to retain heat, and has no protection from the cosmic radiation which constantly bombards it. It is also too cold to support plants, any liquid water on the surface would likely freeze: temperatures on Mars can drop as low as -150 degrees Celsius.
Previously, the only theoretical method of creating plant life on Mars was to terraform the planet, a process which would cost millions and take years, but could potentially create a stable atmosphere similar to Earth’s. Mars’ atmosphere is 95% carbon dioxide, but the air is too thin to support life.
Dust is also commonly picked up and whipped into dust storms which can encompass the entire planet, which would damage or destroy any unprotected plant life.
However, scientists at Harvard University have engineered aerogel sheets that can facilitate plant growth even on the arid surface of Mars, without the need for drastic measures.
They work by mimicking the greenhouse effect, trapping heat from the sun and warming the ground to a temperature of around 50 degrees Celsius. The sheets are scalable, meaning they could be spread across wide areas of the planet as domes or shields.
Thin layers of aerogel already function as insulating blankets that keep the Mars rovers warm at night.
Learn more about aerogel.
The aerogel is made of 97% air, with a silicone network which can block harmful UV radiation while still allowing light through for photosynthesis.
The best place for this would be near human settlements, which would be at optimal locations for sunlight to support the plants as well as the human colonists. It would also grant them easy access to food.
The technology will be tested in extreme desert environments on Earth, like the Arctic or the Atacama Desert in Chile.
Having the ability to grow food on another planet is one of the most important elements in a long-term sustainable colonisation project. Alongside air recycling and waste management, this is one of the main challenges facing anyone looking to live on Mars.
We will likely see humans living on Mars before the end of the century, and this technology might be the first step in our interplanetary journey.