Plants grown in Apollo lunar regolith | Hacker News Reader

Plants grown in Apollo lunar regolith

nature.com

158 pointsperihelions70 comments

This is cool to see, especially because I've been thinking about life on the Moon quite a bit this week (aka reading the Wikipedia article about the 2019 Beresheet lunar lander crash with those sturdy little tardigrades onboard). One article led to another, as they do, and I ended up writing a weird short story about life on the Moon a few days ago:

https://f52.charlieharrington.com/stories/plastic-man-on-the...

So just plain regolith was used? I wonder if it was augmented by fertilizer how much of a difference it would make (a la The Martian)?

"Each well contained 900 mg of regolith material layered over a 0.45-micron filter and Rockwool wick and was sown with 3-5 Arabidopsis seeds suspended in water"

looks like it was as true to the source as possible.

wish they had another 12 grams to test with fertilizer.

They applied "nutrient solution of 0.125× strength MS nutrient solution, pH 5.7 (Murashige and Skoog)". The salts in that make a typical complete hydroponic fertilizer.

https://en.wikipedia.org/wiki/Murashige_and_Skoog_medium

oh shoot, my bad. if that was in the article i missed it.

A few years ago I was writing a (semi-)scientific paper ("Seminarfacharbeit") with two other students as part of the high school graduation process (Abitur) in Germany. The general topic was water and air recycling/purification and plant nurturing for long duration space trips such as a trip to Mars. In the course of writing the paper we had access to a Mars regolith simulant with a very analogous chemical composition to real Mars regolith. We experimented with growing tomatoes, soybeans, radish, spinach and some salad variant I don't remember the name of, each with and without fertilizer. We did'nt have a lot of time and not enough regolith simulant to get significant results, but after a month tomatoes, soybeans and radish showed large growth, with sprout shoots of up to 20cm. We also controlled lighting to be more similar to Mars, although there isn't much difference in daytime lengths. Unfortunately we weren't able to control the atmosphere to be similar to Mars atmosphere, so take our results with a grain of salt.

Grain of salt is an interesting comment as most regolith simulants do not include the perchlorates

I'm guessing that they would have added some simple nutrients and tried with plants you would find in e.g. deserts that are used to grow in very low quality soil.

Over time, you could probably make the soil richer simply by supplying simple nutrients and chemicals and letting nature do its thing. The importance of that is that there would be no need to transport many tonnes of earth soil. Though using some of that would probably help bootstrap soil production.

Chemical fertilizers are mainly produced using simple chemicals (hydrogen, ammonia, phosphates, etc. So, you could see that happening on e.g. Mars which probably has most of what you'd need in some form. I guess the Moon would be more challenging as it has no atmosphere and lacks elements like nitrogen and carbon.

Any reason they picked this specific plant?

It is often a model organism in plant studies, similar to mice in drug discovery. Mostly because it has a quick growth time, is fairly hardy, and just the fact it has been so well studied means that a lot is known about it.

I am not a plant biologist but have talked to some and I've often seen it used in their work and this was their given reasons.

This is all true, plus as the sibling post mentioned its small genome size. The complete genome sequence is about 125 million base pairs, coincidentally around the same size as the other model organisms Drosophila and C. elegans, and only about 10x larger than brewer's yeast (S. cerevisiae). Interestingly I'm not sure if this was known when they started using it, since IIRC Arabidopsis was commonly used even before DNA was confirmed to be the genetic material in the 1940s.

I worked in one of the labs that did the original sequencing and annotation of the Arabidopsis genome, and I can confirm that it was useful to be able to open the complete genome sequence file in an Emacs buffer without my Sun pizza box workstation breaking a sweat.

Wikipedia says its small genome and short "cycle time" makes it an excellent test subject for various experiments. A photo depicts it growing in sidewalk cracks.

Maybe they'll pick an orchid next time!

> Maybe they'll pick an orchid next time!

I feel an Axiom of Choice joke in there somewhere, for the botany + set theory geeks out there...

As others have mentioned it’s basically the foundation of plant biology/genetics. There are entire labs of the top minds in plant genetics working on similar lines of this single plant. Papers/PhDs are published every day characterizing arabidopsis genes, how they interact with other genes, and then how it all changes under different natural or artificial conditions. Because many plant genes are conserved across species, this translates to insights (or gives a good starting point) for researchers working on other plants (or more applied areas like crop improvement).

Is a famous organism in genetics. It grows and blossoms really fast and is well known so you can watch a lot of generations in less time than other plants. Is also conveniently small, so you can culture a lot of specimens in your valuable laboratory space. Is also a Brassicaceae, that are VIP (Very Important Plants) in our agriculture.

Amazing.

I wonder if other plant species are better suited to growing in Lunar “soil”. Just like on Earth plants prefer one type of soil to another.

Interestingly ionic stresses on plants is not a problem unique to the moon - There are plenty of places on earth where(relative to typ. earth soil) high salinity soils exist :

https://www.agriculture.com/crops/cover-crops/new-life-for-s...

With a little bit of selective breeding and genetic manipulation moon diets might include a lot of specialized barley and sugar beets!

Salicornia do really well in salty marshy areas and are edible!

I'm picturing the solar system's first batch of actual moonshine.

Which for that very reason is a feature in every single piece of space-based sci-fi ever

At least _prior_ to knowing anything else about regolith, aside from it sometimes having volcanic origins: Speaking as a person who grows a wide variety of woody tree species (pines, maples, junipers, cottonwoods, azaleas, etc) in inorganic substrates like pure perlite, pure lava, pure pumice (+combinations of those and other volcanic media), and has seen all of these tree species happily send roots into things like IKEA astroturf or blocks of Rockwool, it doesn't surprise me that regolith could maybe work as a grow media.

Fascinating... dare I ask, is that a hobby? A very unusual job?

Bonsai. Hobby for me, but unusual job for my mentors.

Is it not the case that they'd be 'looking' for good soil beyond those surfaces, even if it wasn't there?

It makes sense evolutionarily to 'just work' when possible, especially since the alternative is death

> pure lava,

Is this jargon for some lava-derived rock like obsidian or basalt? Because I'm fairly sure even extremophile bacteria, never mind any kind of tree, wouldn't be able to grow in actual (ie molten rock) lava.

just litter the moon with seeds see what does good

What surprised me the most about this story is that apparently nobody tried this obvious experiment in the last 50 years. It seems basic to supporting a settlement on the Moon.

My understanding is that we have only a small sample and growing things in it would ruin it for a lot of experiments.

These have got to be the most expensive flowers in history.

I dunno, inflation has really hit weed prices lately.

More than Tulips?

Reference: https://en.m.wikipedia.org/wiki/Tulip_mania

> a Viceroy Tulip was worth upwards of five times the cost of an average house at the time.

We do have 382 kilograms of lunar samples returned form the apollo missions - not sure how much of that is regolith though

I'm surprised given that some people had experience growing plants in sand, in water, in air, in some synthetic soils. Is the lunar soil somehow worse than that? Why?

That was my question as well. But I think the article says the scientists didn't know if something in the lunar soil would actively inhibit plant growth.

It looks like the answer is no, and you can use it as an effective substrate for what is essentially a hydroponic type setup where the nutrients are all added.

It is worse for Earth plants due to long term exposure to solar radiation and direct meteorite impacts. Article states that Iron in the moon soil is Fe2, while on Earth it present as Fe3. Another major difference-is silicates and glass composition on the moon. Those are formed by micro meteorite impacts and very different from earth volcano samples.

So plants in moon soil had to adapt a lot more then expected. Also difference between actual moon soil and Earth's moon soil replacement for labs is clearly visible.

You can grow plants in a can of steel bb’s, ground up gummy bears, sand, shredded beer cans, etc….

The matrix isn’t important to most plants. Just the nutrients it gets.

Any hydroponic pot grower knows this.

Does bacteria in soil play no part? It was mentioned in a Peter F Hamilton sci-fi book when talking about terraforming the world "Far Away" - no idea if the bacteria thing real or made up though!

Bacteria and fungi are an important part of soils. It's part of the reason that there are culture solutions you can purchase for gardens.

Mycorrhiza for example is very important for the growth of certain types of herbs and vegetables (and really just a large number of plants in general).

Likewise bacteria are one of the major legs of one of the major ecological processes that's essential for sustaining life on Earth (the nitrogen cycle). The bacteria in soil convert nitrogen gas from the air (which breathes into the soil) into various nitrate compounds which are then absorbed by plants' roots (this is why fertilizer often contains ammonium nitrate). Bacteria are also involved in the phosphorus cycle as well however to a lesser degree. Really micro-organisms in the soil are involved in varying degrees for each of the biogeochemical cycles that life on earth depend on.

Thank you for explaining that !

So you mean if the plants wouldn't suffocate from lack of CO2, wouldn't instantly freeze or dehydrate and not have their DNA destroyed by the radiation, then settlers could actually harvest them and prosper? Yeah, wonder why no-one thought about that.

Clearly there's going to be plastic shielding in the balloon style green houses they will build with the right air mixture. /s

Real lunar regolith is not available for experiments like this. However you can buy simulated lunar regolith, it’s very expensive but not nearly so as the real thing.

Real lunar regolith is available in mass quantities, but the ports are just backed up. Not many ships flying round trip to the moon recently

Well, that's not surprising, what with all these Covid supply chain issues and all. I'm sure it'll be resolved soon.

No one has made credible plans towards supporting a settlement on the Moon in the last 50 years, either.

Experiments have been ramping up over the past couple decades with both Luna- and Mars-analogous simulated regolith. The novelty is doing it on real regolith brought back from Luna.

Only vaguely related, but it'd be interesting if NASA engineered a self-contained terrarium-like ecosystem, put it in orbit, and watched what happens.

No need to put it in orbit. A self-sustaining sealed ecosystem is a vital piece of research and engineering for us to do before we leave the planet.

The failed Biosphere 2 project was one such attempt.

https://en.m.wikipedia.org/wiki/Biosphere_2

I always found it odd that such an important line of research was restricted to one-off stunts like this. Every university should be making sealed gardens.

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