Earthworms can reproduce in Mars soil simulant | Hacker News Reader

Earthworms can reproduce in Mars soil simulant

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138 pointsscadge75 comments

It's crazy how scientists are researching worms for Mars and yet our scientists in agriculture actively preach practices that compact soil and kill soil biology. Monsanto chemicals and John Deeres tractors are ruining systems that literally self renew.

Maybe we should try to work with earth's nature here before trying to emulate it on another planet?

Why can't you do both?

My family are based in New Zealand and make a feriliser that is high in carbon and micronutrients (we use seaweed). Even after pot trials and field trials showing massive benefits we found it nearly impossible to sell to farmers. Generally they are sick of snake oil salesmen peddling the next best product. Farmers mindsets are almost immutable - we even had farmers who used some and saw the anecdotal benefits (worms) and then just switched back to regular SSP because it was what they always did. We had a lot more success with vineyards.

Could it be because it is impossible for the farmers to determine long-term effects (e.g. damage to the soil, etc.), and they don't want to risk adopting a potential "time bomb"?

Yes it certainly could be that. The margins for sheep & beef farmers especially are quite thin so they are essentially surviving year to year and wouldn't want to risk even a short-term impacts.

Although I would argue that some of it is common sense which is eschewed because of the thin margins. In NZ, farmers will annually replace phosphate, nitrogen, and potassium because they know it is lost to produce/erosion/environmental factors. But the same isn't true of 20+ other nutrients that make a healthy soil. Soil is like the human body which has an amazing ability to survive on just bread and water, but that doesn't necessarily mean that's all you should feed it

Appreciate the answer and good luck with the venture.

Do you have a source for any of this?

I believe he's referring to the usual Monsanto horror stories, which always receive plenty of discussion on HN.

Try putting "monsanto" in the search field at the bottom.

https://www.youtube.com/watch?v=q1aR5OLgcc0

For more on this topic, please research:

- no-till farming

- polycultures (no monocultures)

- cover crops (or cover soil when not in use)

- reduce or eliminate chemical inputs

- permaculture

Most farming is no-till now, because of the "chemicals" you seem to hate.

That is false. Most farm land is tilled, plowed, driven on by machines for seeding and harvest, and disturbed regardless of the chemical inputs.

I can only speak for my region. But plowing and cultivating has become a lot less common over the past few decades. Herbicides kill the weeds effectively which reduce the need for it.

I think you don't know what you are talking about.

This tendency of "solve this problem first, instead of this other thing" is rather unfortunate. Why not work on both? Or get the right people to fix what you'd like?

Using earthworms is not new at all - this has been going on for hundreds of years in agrarian societies.

I didn't say it was new, I said we are actively killing earth worms on our planet and destroying self renewing systems. One doesn't have to "use" earthworms, they are part of nature and work without needing any guidance our inputs. Simply leave the worms and other soil biology alone and they self renew!

But can they reproduce in the soil at the same range of air pressure found in habitats, with the same gravity / gas mixture? Can they still reproduce after 50 years?

You could make pressurized greenhouses on mars to simulate earth conditions.

Inflatable, radiation shielding, light emitting? How.

Edit: Plants and non-human animals wouldn’t appreciate Martian rads either.

They don't really need to be radiation shielding or light emitting. People don't need to live there, just plants and animals. And insolation on Mars is sufficient for light.

Excessive radiation can also kill plants and animals

Even before it kills them, it definitely ruins their reproductive capacity, which is going to be critical offworld.

We could have a breeding population in an expensive shielded environment, and take most of their young to grow in a cheap, more radioactive environment.

Now that’s a really interesting idea! Add in a bank of shielded frozen embryos and sperm and yes, I can see your point.

Is the radiation on Mars excessive? Quick googling suggests 10-20 rem per year, or about half that of the ISS. As far as I know plants do grow on the ISS.

Plants are pretty tolerant of solar radiation. Far more so than humans.

In any event, what you'd probably do is use reflected light to filter out high energy particles.

Background radiation in Mars is way lower than would be necessary to kill plants and, like, it might increase cancer rates in animals, but the kind of animals we'd want to breed there have short lifespans and we don't care if they get a few tumors.

Underground, LEDs, hydroponics?

Sure, but now you’re spending the Dv to get all of that to Mars.

Still much cheaper than shipping dirt to Mars.

It's even cheaper to construct and use all that stuff on Earth.

Not risk adjusted.

Compared to the risk of Mars? I take your point, but let’s be realistic about our odds on Mars without Earth backing it all up.

Granted. And initially, sure, but aiming long term for a single-planetary culture that took 3.8 billion years to develop seems shortsighted.

The risk of that life snuffing out may be small, but the time cost of replacement should that happen is huge.

That doesn't help a establish a Mars colony, which pretty much rules out that option if you want to establish a Mars colony.

It does, because you can figure out how to make all this stuff work[1] without spending hundreds of billions of dollars going to Mars. You'll also probably discover that you don't actually want to establish a Mars colony.

[1] We don't actually know how to make it work. The Biosphere 2 project was a spectacular failure, and it operated with a much less difficult set of constraints.

Need to run that experiment on the ISS in a Mars-gravity centrifuge.

Despite a lifetime of 6-9 years, though, their generation length is only a few months; if they reproduce in that radiation environment for a year or three and there aren't serious mutations, they'll probably be okay in the long run.

And in a few generations probably evolve to build further resiliency for the subject radiation/gravity/air pressure conditions.

If these habitats are also housing people, then the atmosphere will likely be very close to Earth pressure and composition.

The atmospheric pressure on the ISS is very close to 1 atmosphere, and it's an oxygen-nitrogen mix close to earth's atmosphere.

A mars mission won't be getting frequent short-hop trips from earth. I would expect the habitats to use reduced-pressure atmospheres with less to no nitrogen.

Then everything needs to be made of fire-retardant materials. Reducing the nitrogen content of the atmosphere has little deleterious effects for people, but makes fires easier to start, hotter, and harder to put out.

If you reduce the amount of nitrogen, and don't replace it with oxygen, it doesn't have all that big of an effect on fires. And in trade it becomes vastly easier to contain the pressure.

Yes, it really does.

The issue is that the inert nitrogen has a really important role in carrying away heat from the flame. Fire is a dynamic reaction where temperature and speed is determined basically by how much heat a set of reagents produce/how much heat is carried away in the waste products. Nitrogen doesn't participate in the chemical reaction, but it gets heated alongside the waste gases, and so it reduces the temperature of the fire.

In a pure 0.2bar oxygen atmosphere, anything that would smoulder or burn slowly in standard atmosphere burn rapidly with a bright flame instead, and some things that you'd normally not consider flammable can sustain flame.

This is the reason the space station maintains a normal atmosphere instead of a thin pure oxygen one.

Conversely, if you double the amount of nitrogen (without reducing the amount of oxygen) in the air, almost nothing burns anymore.

What would you expect the habitats to have instead of nitrogen? You wouldn't want a high oxygen atmosphere. Not only is it an extreme fire risk (see Apollo 1), but humans aren't built for it - oxygen toxicity exists.

Nothing. He said reduced pressure.

Those are both hazards from having too much absolute oxygen, not too much relative oxygen. Our current launch craft use an atmospheric mix so they are safe on the launchpad, and the ISS uses an atmospheric mix to easily interface with those launch craft. On mars you don't need to worry about space shuttles coming to visit, so .25atm of mostly-oxygen would be fine.

The atmosphere of Mars contains nitrogen. It could be extracted and concentrated to provide the same percentage as earth's.

If not, maybe we can engineer a breed of worms that can.

I'll paste in my previous comment about this. The tone is bit harsh, the context was more hypeful

> Ugh. I feel like Wamelinks researchs importance is way overblown. Hydroponics has shown that you need no soil to grow plants, so is it really surprising that Mars soil simultant that has been specifically treated to be friendly can sustain plants and worms? Especially when the simultant might not have been very accurate chemically to begin with. Personally I think the first generations will be using heavily hydroponics, and during that period can do actual in-situ experiments that are far more informative than anything we can do here on earth.

> Direct quote from their 2014 paper (I couldn't find the earthworm paper, links would be appreciated):

> > Our results show that it is in principle possible to grow plants in Martian and Lunar soil simulants although there was only one plant that formed a flower butt on moon soil simulant. Whether this extends to growing plants on Mars or the moon in full soils themselves remains an open question. More research is needed about the representativeness of the simulants, water holding capacity and other physical characteristics of the soils, whether our results extend to growing plants in full soil, the availability of reactive nitrogen on Mars and moon combined with the addition of nutrients and creating a balanced nutrient availability, and the influence of gravity, light and other conditions.

It’s not just about food though, is it? Being able to grow plants on mars is, I would have thought, an important step for terraforming.

Also, if we work out which plants kinda work, we might be able to isolate the genes that improve survival and add them to other plants.

Absolutely. The far better way to grow is sans-soil. Aero or hydroponically. Even inert grow materials like coco are fantastic and highly reusable.

It's not like we are going to be growing outside on Mars anyway. It will need to be under UV LEDs and solar powered. I expect the energy use of reclaiming the water from the air would be more than would be saved by trying to use solar lighting.

I like the idea of terraforming mars, but it seems like we are still going to be stuck living in bubbles anyway since it has no core or ability to block the various solar / cosmic waves that would wreck plants and animals and blast away any attempts at building a atmosphere.

If you find this interesting you might appreciate the Red Mars series by Kim Stanley Robinson.

If we are able to conclusively determine that Mars is no longer host to life, should we try to seed the planet with carbon dioxide & methane producing organisms in order to create an atmosphere?

That wouldn't do much good unless we can re-establish the magnetosphere.

Ah yeah, forgot about that. And restarting the core dynamo seems pretty infeasible regardless or our technological capabilities.

I think it is still an open (and hotly debated) question on if planets need magnetospheres to retain an atmosphere.

A magnetosphere is required to shield from charges particles and other harmful radiation.

* also, retain an atmosphere "over long enough timescales"

From the MAVEN research papers I've read, we're talking ~5,000 metric tons / yr of atmosphere being stripped.

Which is a lot, but not an insurmountable lot.

Mars has isolated pockets of "mini magnetospheres" that are suitable enough to block charged particles.

http://www.space.dtu.dk/english/Research/Universe_and_Solar_...

I think he was assuming the subject was terraforming.

Without a magnetosphere, the atmosphere will keep being blasted off into space continuously, and it'll be impossible to terraform.

Continuously, but slowly, over very long time scales. Maintaining an atmosphere suitable for us is probably far easier than constructing it in the first place.

I don't think that's necessary. The loss of atmosphere by Mars may have been significant on the timescale of its five-billion-years history, but not on the timescale of a human settlement project.

The mass of the Martian atmosphere is about 25 teratonnes [1]. According to the measurements by MAVEN, the rate of mass loss by Martian atmosphere due to solar wind is 100 g/s [2]. At this rate it would take

    25e12 * 1000 * 1000 * 0.01 / 100 / 3600 / 24 / 365.25 = 79 million years

for Mars to loose 1% of the mass of its atmosphere. Even if the rate of mass loss were 10 times higher than measured by MAVEN (it's known to increase during solar storms and in perihelium), it'd still take nearly 8 million years.

Looks like if we can increase density and pressure of Martian atmosphere as GP suggested, we don't really need to worry about the lack of magnetospheric protection.

[1] https://en.wikipedia.org/wiki/Atmosphere_of_Mars [2] https://www.nasa.gov/press-release/nasa-mission-reveals-spee...

Of course it would turn out that the first thing we could grow and eat on Mars would be rocket.

For the confused, rocket is called arugula in American English [1].

[1] https://en.m.wikipedia.org/wiki/Eruca_sativa

And sometimes spelled as roquette

Did they include perchlorates in the simulated Martian soil? It seems unlikely that they did but I might be mistaken.

The big issue with either growing plants on Mars or simply being exposed to Martian dust is perchlorates in the soil: https://www.space.com/21554-mars-toxic-perchlorate-chemicals...

So it might work! Can we boostrap a real, nutrient-rich regolith and ecosystem from scratch? That would be some amazing terraforming - and some major value for mankind.

And here I thought The Martian's most unrealistic part was growing the potatoes.

The Martian is still pretty unrealistic. It's not possible to get enough light using the setup described in the book.

The most unrealistic part was the dust storm in the beginning. Not enough air pressure on Mars for wind to do much.

Somebody did the math: https://space.stackexchange.com/questions/9301/could-you-fee...

I feel like sending earth worms to Mars is like sending pigs to South America. Perhaps there is nothing living there... I don't know. But do we need to have such an imperialist attitude with planets too?

Imperialism is not a bad thing.

Successful species spread and thrive. Failed species are extinct -- and we will be too if we don't get off this rock.

That sounds like the mantra of an anthropomorphised virus. But my down-votes seem to suggest it's popular opinion here.

I'm just saying there was more to learn from America than "potatoes and corn are good".

Some things live in a realm "beyond good and evil" and are just pure creation. I think Mars terraforming is one of those things. We are creating an entirely new system within which new goods and new evils might subsist. The entire notion of "Imperialism is bad" is a banal historical platitude in this context.

I wouldn't judge it that bad. "it" is not a popular opinion, and the downvotes are due to a sensitive topic and a biased crowd if you consider the time of your posting. "it" seems popular because, ironically, everyone else just does not care enough to spread their seeds of wisdom.

Who knows, we might even manage to make ourselves extinct.

It's a barren rock. You're not displacing native lifeforms, because there are no lifeforms. It's as imperialist as shouting "I'm the king of the world" in Antarctica.

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