How We’ll Grow Food on Mars Without Earth

With verbals, last-minute deals, you can save over $50 on your spring getaway.

So whether it's a mountain escape with friends, a family week at the beach, or sightseeing

in a new city, there's still time to get great discounts.

Book your next day now.

Average saving $72, select homes only.

Welcome to Bedtime Astronomy.

Explore the wonders of the cosmos with our soothing Bedtime Astronomy podcast.

Each episode offers a gentle journey through the stars, planets, and beyond, perfect for

unwinding after a long day.

Let's travel through the mysteries of the universe as you drift off into a peaceful slumber

under the night sky.

Picture this.

You're standing inside a habitat on Mars.

Right.

Millions of miles from home.

Exactly.

And outside the reinforced glass, it's just this freezing, irradiated, you know, completely

toxic desert.

There's literally nothing but red dust and freezing winds.

Shounds pretty bleak.

Yeah.

Right.

But inside, you're sitting down to a meal, and you're eating a fresh, crunchy, incredibly

protein-rich green salad.

Oh, wow.

Okay.

It's a truly mind-bending part of this scenario, not a single ounce of soil, not a single

drop of fertilizer, not even the water used to grow that food was brought from Earth.

It's a profound shift, really, in how we think about survival, because everything on your

plate in that scenario, it was generated from the dead, barren environment right outside

that window.

It sounds like pure science fiction, right?

But this is actively becoming reality.

A research team from the Center for Applied Space Technology and Microgravity, along

with the University of Bremen and the German Aerospace Center, they've successfully produced

a fertilizer made solely with Martian resources.

Yeah, to grow edible biomass.

It's incredible.

Okay.

Let's unpack this, because what we're really talking about here is a masterclass in ultimate

sustainability.

I mean, it's about engineering life in a completely dead environment, relying only on what is

already there.

And that's, you know, that's the crux of the challenge, because when you look at Mars,

you're looking at an environment that actively resists life.

The dirt on Mars isn't soil.

Right, it's just dirt, or it will dust.

Exactly.

Soil, as we know it here on Earth, is a living matrix.

It's teeming with microbes, decaying organic matter, earthworms, fungi, I mean, earth

soil is a biological engine.

But Mars is just dead rock.

Yeah, Mars is covered in regolith.

It's crushed volcanic rock, heavily oxidized by billions of years of solar radiation.

It's completely sterile and entirely devoid of the bioavailable nutrients that, you know,

complex plants need to actually grow.

So you can't just take a potato, shove it into Martian regolith, and expect it to sprout,

no matter what the sci-fi movies might show us.

No, definitely not.

The dirt is just lifeless rock.

So to understand how we get a fresh salad on a dead planet, we first have to solve that

fundamental problem.

We need an intermediary, right, something that can bridge the gap between sterile rock

and complex plant life.

And that brings us to the hero of this entire process, cyanobacteria.

Ah, blue-green algae.

Exactly.

These are some of the oldest and most resilient living organisms we know of.

They're essentially the microscopic pioneers of our own planet and now, potentially, of

Mars.

Because they can handle the harsh conditions.

Yeah, they have a few incredible biochemical properties that make them perfectly suited

for this job.

First, they're photosynthetic, but highly adaptable.

They pull carbon dioxide directly from the thin Martian atmosphere.

Which is crucial, since Mars' atmosphere is what, about 95% carbon dioxide?

Right.

Exactly.

So they're pulling their carbon straight from the air and producing oxygen as a byproduct.

But breathing in CO2 doesn't solve our dirt problem.

The real magic has to be happening and how they interact with the regolith itself.

What's fascinating here is their ability to literally eat rock.

Eat rock.

Literally.

Literally.

Yes, literally.

Doctors prove this using something called MGS-1.

It's an artificially produced regolith that perfectly mimics Martian dust.

Because we have decades of spectroscopic data from the Mars Rovers, right?

Exactly.

So we know the exact mineral composition of the surface.

We know it's full of basalts, pleasure clays, and olivine.

And just to clarify, for anyone imagining standard earth rocks, things like olivine and

pleasure clays are critical here, they lock away the heavy metals and nutrients like

iron, magnesium, calcium, that biological life desperately needs.

Right.

But the problem is those nutrients are trapped inside a rigid, crystalline structure.

They're locked in a geological vault, essentially.

Plants can't access them.

But cyanobacteria, they don't just sit on the rock.

They chemically weather it.

Like breaking it down.

Yeah, this is a great highly specialized organic acids and binding agents called cydrophores.

These compounds literally dissolve the mineral lattice on a microscopic scale.

Wow.

They're freeing up the trapped iron, phosphorus, and sulfur, and pulling them directly into

their own cellular structures.

It's wild when you visualize it.

I mean, these microbes are basically the ultimate cosmic off-grid preppers.

Ah, that's a good way to put it.

They're just secreting acid to dissolve rock and building a full meal out of thin air and

crushed dust.

Hmm.

But I have to push back a little in the logistics here.

Sure.

Because eating rocks is great for the algae, but humans can't eat the algae directly, right?

A bowl of raw cyanobacteria isn't safe.

And it's certainly not the crunchy salad we talked about.

How does this actually help us?

You're completely right.

The algae isn't the food.

It's the raw material for the plant food.

Oh, I see.

You have to think of these microbes as a necessary biological bridge.

Complex plants that humans want to eat are relatively fragile.

They demand their nutrients in very specific, easily absorbable forms.

Mostly as ammonium and nitrates, right?

Exactly.

They cannot break down rock, cyanobacteria can.

So the microbes do the heavy lifting of pulling the minerals out of the rock and incorporating

them into their own biological cells.

Once the cyanobacteria have multiplied and created a massive amount of cellular biomass,

we then take that biomass and use it to feed the plants.

Okay, so we have a tank full of rock-eating microbes packed with Martian nutrients.

Great.

But since we can't eat the algae and a plant can't just absorb a living microbe, we have

to process it.

We do.

We have to unlock those nutrients.

We have to break the cell walls of the algae down so the plants can actually use what's

inside, which brings us to the fermentation factory.

Right.

This is where the engineering really meets the biology.

You have tanks full of this cyanobacterial biomass, rich in carbon, nitrogen, and Martian

minerals.

To make those nutrients available to plants, you have to break the lipid bilayers of the

cell walls down.

How do they do that?

Do an anaerobic fermentation process entirely without oxygen?

Which strikes me as incredibly vital for Mars.

I mean, if you used standard aerobic composting, like we do in our backyards on Earth, you'd

be relying on oxygen-branding bacteria.

Exactly.

On a Mars habitat, you'd be stealing the exact same oxygen the astronauts need to stay

alive.

Right.

So, by using an anaerobic process, you're using microbes that thrive in an environment

without oxygen, doing all the decomposing for you without tapping into the habitat's

support.

It's a massive advantage.

It uses only materials that are potentially available on site.

But this process isn't just a matter of throwing the algae in a sealed tank and walking

away.

Wait, so we're just letting space algae rot in a warm, airless tank?

How do we know it's actually creating the right kind of fertilizer?

It's highly calculated, not just rotting.

A 2026 study in the Chemical Engineering Journal detailed the precise optimization parameters

required.

So, it's a very specific recipe.

Very specific.

The researchers discovered that if you hit the biomass with a thermal shock, first essentially

heating it up, it weakens those cellular walls.

That leads to much faster, more complete decomposition once the anaerobic microbes go to work.

And faster decomposition is obviously critical when you have hungry astronauts waiting for

a harvest.

But if we're breaking down this massive bloom of algae and a digester, that presents a

massive chemical balancing act.

And earth, if you mess up the nitrogen mix in your fertilizer, you burn the roots and

kill the crop.

Right.

Which is why they had to meticulously determine the exact ratio between the amount of

cyanobacterial biomass used and the resulting ammonium yield.

Because ammonium is the holy grail for plant growth here.

Exactly.

It provides the bio-available nitrogen plants need.

The researchers mapped out exactly how much dry biomass to add, factored in the thermal

shock, and found the exact Goldilocks zone for the temperature.

Meaning they found the perfect temperature where the anaerobic microbes work at maximum

efficiency?

Yes.

Exactly.

35 degrees Celsius.

Maintaining the digester at that temperature is the ideal thermal state to release the nutrients

without degrading them.

So you input X amount of rock eating algae, hit it with a thermal shock, hold it at 35

degrees without oxygen, and you get why I'm out of perfectly balanced liquid plant food.

Precisely.

It's a closed, predictable, and repeatable manufacturing process.

Okay.

So now we have our perfectly engineered 35 degree fermented Martian fertilizer, the biological

bridge is built.

Now we need a crop that can maximize it.

We do.

And we aren't growing standard earth potatoes, like in the movies.

Right.

Because a potato plant produces a lot of stems and leaves that you can't eat.

It takes months to grow at waste's energy.

We need something far more efficient.

In a space habitat, every square inch of space, every drop of water, every photon of light

is precious.

You cannot afford to waste energy growing biological structures that you're just going

to throw away.

You need a crop that offers an incredible return on investment.

Enter duckweed.

Ah, yes.

Lemnelspeak.

Yeah.

If you've ever seen a pond covered in tiny, bright green leaves floating on the surface,

you've seen duckweed.

And it turns out it's the ultimate space crop.

It really is a marvel of botany.

It's a fast-growing, highly protein-rich aquatic plant.

And it doesn't need soil at all, right?

None.

Exactly on the water, absorbing nutrients straight from the liquid.

That makes it uniquely, perfectly suited for our liquid cyanobacteria fertilizer.

And you can eat the whole thing, no stalks or husks.

Exactly.

It reproduces by essentially cloning itself, doubling its biomass exponentially in a matter

of days.

It's been safely consumed in Southeast Asia for centuries, actually.

They call it water lentil.

It's even already approved as a food in the EU.

Here's where it gets really interesting.

It's the yield.

The conversion rate is phenomenal.

Yeah.

From just one single gram of dry cyanobacteria, one gram of that processed microbe dust, the

system produces 27 grams of fresh, edible duckweed.

Which is staggering when you consider the original input was literally just atmosphere gas and sterile

crush rock.

It's like a botanical slot machine that hits a 27x jackpot on every single pole.

You put in one gram of prop to algae and out comes a massive handful of fresh, crunchy protein-packed

greens.

It reinforces the gravity of what this system achieves.

As researchers Cyprianne Versonotid, this proves a fundamental concept.

Plants can be grown using purely natural Martian resources, with microbes as the intermediate.

Forming the foundation of a truly sustainable food system.

Yes.

The biological chain from dead rock to human food can be sustained indefinitely without

Earth's self.

But surviving on Mars requires a full stomach, sure, but a sustainable settlement requires

more than just calories.

You need power, heat, lights.

You have to keep the habitat from freezing over.

Exactly.

And incredibly, this biological process actually solves a massive secondary problem for a Mars

base.

It has this highly valuable byproduct.

Right.

When we go back to that fermentation factor, the anaerobic digester, bringing down the

algae at 35 degrees the bacteria, doing that breakdown release gases.

Specifically, they produce methane gas.

Yes.

The anaerobic fermentation process essentially acts as a miniature biogas plant.

As the fertilizer is being created, methane is bubbling up through the liquid.

Wow.

And this methane can be captured, pressurized, and utilized as a vital energy source for

the settlement.

So what does this all mean?

Usually agricultural byproducts are a massive waste management headache.

But here, the quote unquote waste might power the lights in the habitat.

If we connect this to the bigger picture, you start to see the elegant architecture of

total closed loop self-sufficiency.

Because we can't just keep shipping soil and fuel from Earth.

Right.

It's economically and physically impossible.

As researcher Tiago Ramallah pointed out, running a system entirely on local resources

without bringing any supplies from Earth is the only way future Martian settlements can

survive long term.

It's the ultimate closed loop.

The Martian atmosphere and dust feed the algae.

The algae makes fertilizer and methane.

The methane powers the habitat.

The fertilizer grows the duckweed.

The humans eat the duckweed, exhale CO2, which goes back to the algae.

Nothing is wasted.

Every single atom is recycled and given a purpose.

It's amazing.

But I want to bring this back from Mars to Earth for a second.

Because you listening to this right now might be thinking, well, I'm not moving to Mars

anytime soon.

Why should I care?

It's a fair question.

But duckweed is currently being considered a sustainable superfood of the future right

here on our home planet.

The agricultural challenges we face on Earth are mounting rapidly, with severe topsoil

erosion and depleted natural fertilizers.

Traditional farming is incredibly resource intensive.

It uses vast amounts of fresh water in land and relies on chemical fertilizers that

damage aquatic ecosystems.

But duckweed changes that math.

Because it grows on water, it doesn't require massive tracks of arable land.

It produces more protein per acre than almost any terrestrial crop, including soybeans.

So the technology designed to keep astronauts alive could revolutionize human agriculture

right here on Earth.

Exactly.

The unforgiving constraints of space travel force us to be perfectly efficient.

When you bring that closed-loop technology back down to Earth, it offers a blueprint for

how we can heal our own damaged agricultural systems.

We learn to do infinitely more with infinitely less.

It's a beautiful irony that looking out into the cold, dead vacuum of space might teach

us how to better nurture life at home.

It really is.

So I want to leave you with a final lingering question to ponder long after you finish listening.

If human ingenuity can engineer a perfectly closed-loop zero-waste agricultural system

to feed people using the dead toxic dust of Mars.

What does that mean for us here?

Exactly.

What does that mean for how we could revolutionize farming in the harshest, most depleted environments

right here on Earth?

Could the key to saving Earth's soil ultimately come from a planet that doesn't have any?