Foods That Fare Best In Martian Soil

Let’s admit it. Outbreaks such as (or much deadlier than) COVID-19 will become more prevalent in the years to come. With global warming, surging demographic pressure and habitats destruction, our confrontation with unknown viruses that humans have no immunity to is a predestined eventuality.

Other threats that may wreak large-scale destruction on the planet will come from outer-space, such as asteroids and comets. It also would be a massive understatement to say there wouldn’t be any nuclear, biological or chemical warfare.

To escape from these impending horror shows, voyage to Mars seems to be the only way out. But, why Mars?

The size, distance from the Sun, and extractable liquid water beneath its surface make Mars the best candidate for an extraterrestrial human colony.

Mars colonization isn’t in the cards for humanity anytime soon, but scientists are gearing up to establish a human settlement there by as early as 2033. Also with SpaceX comprehensive vision to develop Mars transportation infrastructure, colonization of Mars could come much earlier than anticipated.

Weighing the feasibility of these approaches by NASA and SpaceX, faculty and student researchers at Villanova University pioneered the “Red Thumbs Mars Garden Project” in 2017 to investigate which variety of vegetables and herbs can thrive in Martian soil simulant (MSS).

Martian soil simulant (or Mars regolith simulant) is an iron oxide-rich basalt which has been prefabricated to simulate the chemical and mechanical properties of Martian topsoil by addition of chemical agents.

Based on the Mojave Desert, the regolith simulant has 90 percent similarity with the regolith found on the Martian surface, but with the exception of perchlorates that are toxic to humans. So before we make a settlement there, removing this dangerous chemical from the soil must be one of the top priorities.

Mars might have been inhabitable a few billion years ago. While I can’t say for sure that it was similar to earth in its makeup, it once boasted oceans and lakes. It also had temperate climate which scientists believe were favorable enough for organisms to flourish. But now it has its magnetic dynamo shut down by heavy asteroid blows, atmosphere and water inventories stripped away from its surface by extremely violent solar storms, and with nothing to protect against the scourges of solar radiation and cosmic rays, its surface was left to suffuse with poisonous perchlorates.

Water (mostly as ice) exists under its surface, however, as well as in the planet’s frigid zones.

Moreover, Mars is relatively small, having only 10 percent the Earth’s mass. It’s also cold with temperature averaging minus 60 degrees Celsius (minus 80 degrees Fahrenheit). The atmosphere is made of 95 percent carbon dioxide, and 2.5 percent nitrogen, but the pressure is about 1 percent of the Earth’s.

Also, since it orbits the Sun at a much greater distance – of roughly at 141 million miles  (228 million km ) – the maximum intensity of sunlight on the planet is much less (44 percent)  than that on Earth. And to cap it all, there’s no ozone in the Martian atmosphere. So, the environment there isn’t exactly human friendly.

In order to perfectly replicate Martian greenhouse conditions, and of course, create a plant-friendly environment, variables such as the amount of sunlight the planet receives, temperature, the types of chemical and organic fertilizers that work, percentage of carbon dioxide and nitrogen – must be accounted for. But can we do that?

Well, that’s what exactly folks at Red Thumbs Mars Garden Project did in their greenhouse experiments. Now, we have a handful of food that fare best in Martian soil conditions.

To make up for these harsh conditions such as thin atmospheric pressure, low temperature, and surprisingly high humidity, the Mars greenhouses the team built are airtight and highly pressurized, and heated.  The experiment also ensured the plants received Mars-like light conditions, so they pared down the exposure to around 44 percent. They also experimented how well some plants responded to hydroponic practice.

They also found that the MSS dried out very quickly, so regular watering was needed. The team estimated that the greenhouses would need to maintain at least 60 percent humidity to avoid soil dryness. The soil was also too dense for roots to penetrate and grow; so they solved this problem by aerating it with potting mix or earthworm feces.

With everything accounted for, the researchers found that vegetables and herbs such as lettuce, arugula, spinach, peas, garlic, microgreens, onions and kale fared best in the Martian soil conditions. Dandelions, too, stood well in the experiment. However, carrots, tomatoes, beans, legumes, and many root plants failed to make the cut as they came out stunted.

Sweet potatoes, too, did well, but low light conditions and the stimulant soil weren’t particularly friendly for potatoes, therefore, they were excluded from consideration.

The NASA and SpaceX’s joint effort to get people to Mars, but also to colonize it, is quite detailed and incontrovertible. With science and technology advancing at jet-propelled speed, we could hit a breakthrough anytime soon and set up colonization on Mars even faster. Also, this initiative by Villanova University is quite exciting, and is nothing short of extraordinary.