Will plants grow on the moon? | Hacker News Reader

Will plants grow on the moon?

worldsensorium.com

85 pointsdnetesn72 comments

Chinese already did a similar experiment few years ago and the result was that "plants can grow on the moon despite the intense radiation, low gravity, and prolonged intense light"

https://phys.org/news/2023-10-china-tiny-farm-moon.html

> Over the next eight days, this payload conducted a vital experiment where it attempted to grow the first plants on the moon.

The plants survived eight days before freezing, but important questions also include things like "How does the radiation impact their seed viability in future generations?"

I'll grant that they didn't immediately die, but neither would I have expected that from an ionizing environment. Just a lot of weird quirks in lifecycle.

You can keep something alive for a week in a terrarium basically anywhere, I'm not even sure their result is interesting if it weren't for the fact that it was on the moon.

We do need to prove basic assumptions on the fairly likely chance that they won’t pan out.

> if it weren't for the fact that it was on the moon.

If it weren't for the entire reason they did the experiment in the first place?

Ionized radiation is dangerous to mammals because of the potential DNA damage that we are so bad at repairing.

Plants on the contrary tolerate much more damage. To the point that we develop new species by bombarding seeds with ionized radiation.

I read about an effort to do this in the 1950s (IIRC, it was in Pawpaw: In Search of America's Forgotten Fruit by Andrew Moore, but I could be wrong about that) and as I remember it, most of the radiated seeds were either sterile or produced deformed offspring.

Did they expose the seeds or the plant that produced them?

Atomic gardens:

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

+ artificial selection by robots, could be a way to generate environment adapted organisms.

>we develop new species by bombarding seeds with ionized radiation

"yes, no problem, because what could go wrong!? Another slice of care-not cake, pls"

Honesty the biggest what could go wrong is things like vegetables will stop producing the useful large fruits we eat if we're trying to grow things for food.

On the contrary: the ones that washed up on the shore of Gilligan's Island were unusually large.

While it sure sounds straight out of some 50s horror movie, I have a feeling the consequences here are pretty insignificant. The mutant tomatoes I've harvested and eaten from my garden have been quite tasty. Any particular fears in mind?

"having a feeling" plus anecdata is not a long term longitudinal study.

Right, nor scary words a threat, hence my ask for clarification.

People doing it everywhere around the world for almost a century now, effectively is. Unsurprisingly for anyone whose understanding of science extends beyond cheap comic book tropes, everything is fine.

Radiation isn't evil magic, mutations don't give superpowers. Both are natural phenomena, and they're not anything like they're portrayed in comic books.

Might as well worry about watering your plants. Plants are perfectly fine, they live and grow by nature magic, no need for humans to play god and add water to the mix, what could possibly go wrong?

What's the difference between atomic gardening and regular selective breeding performed under the giant ball emitting ionizing radiation that we have overhead half the day except the rate at which mutations occur? Plants with terrible nonviable mutations might be entirely sterile even if we like them, plants with viable but undesirable mutations we won't propagate into another generation. It seems akin to modern GMO efforts with a shotgun instead of a scalpel, but it did work.

Plants also handle mutations differently, creating burls and cavities and whatnot instead of it taking over the entire existing plant like cancer does in animals. You're unlikely to generate a Plants vs. Zombies scenario here.

irradiating seeds without irradiating the consumers of seeds creates an opportunity for one-sided evolutionary advantage. see Gojira

That's... literally not how any of this works.

Might as well say that beating grapes into pulp without beating grapes of the consumers gives juice an opportunity for one-sided evolutionary advantage.

This is what nature keeps doing for billions of years - we have constant background radiation, some stuff from sun which still gets through, and lets not forget about everybody's favorite cosmic rays. The most energetic particle we detected had energy of baseball ball thrown at 100kmh. I'd say this is the main fuel of whole evolution of life on Earth, on top of drastically changing environments.

You can't build 100% radiation-shielded environment, anywhere. Neutrinos just don't care that much about obstacles (and interact very weakly with target, but they still do in small numbers, that's how we detect them).

on the scale that nature does it, the consumers of plants also evolve.

I can't believe what I'm being asked to argue here, it's "environmentalism" and "public health" and "anti big X" all rolled up into one. I'm on the other sides of all those issues, so I wish you'd all get back in your lanes.

Nah, you're just arguing magical thinking based on, to put it charitably, an understanding of reality pulled from pulp sci-fi and cheap comic books.

yeah plants tend to be polyploid which helps with robustness to radiation damage.

Have we tried the same with animals?

> Plants on the contrary tolerate much more damage. To the point that we develop new species by bombarding seeds with ionized radiation.

Years ago, I worked with this microbe (https://en.wikipedia.org/wiki/Deinococcus_radiodurans).

"Deinococcus radiodurans is capable of withstanding an acute dose of 5,000 grays (Gy), or 500,000 rad, of ionizing radiation with almost no loss of viability, and an acute dose of 15,000 Gy with 37% viability.[14][15][16] A dose of 5,000 Gy is estimated to introduce several hundred double-strand breaks (DSBs) into the organism's DNA (~0.005 DSB/Gy/Mbp (haploid genome)). For comparison, a chest X-ray or Apollo mission involves about 1 mGy, 5 Gy can kill a human ...."

Some enterprising researchers must have considered engineering this microbe to produce useful products in space, but I don't travel in these circles anymore.

I like how latin names for such organisms are (intentionally) so fitting: "radiodurans".

The Greek half of the name is equally fitting.

But it's just a side effect of being an extremophile with really good DNA repair machinery. The microbe isn't intentionally resistant to radiation. It's not adapted specifically to radiation environments.

That same lander (Chang'e 4) also measured the radiation dose rate on the moon. It's about 2.6x that of the ISS. Doesn't account for solar particle events, which they didn't encounter any.

https://www.science.org/doi/10.1126/sciadv.aaz1334 ("First measurements of the radiation dose on the lunar surface")

- "LND measured an average dose equivalent of 1369 μSv/day on the surface of the Moon."

I'll be very surprised if plants from Earth can tolerate the sort of high radiation environment that is the moon (or space in general, outside the magnetically shielded and atmospherically shielded bubble that is Earth).

We tend to forget that the sun is an incredibly powerful and quite unshielded fusion reactor purring away, pushing 1000W/m^2 through our atmosphere. It's about 1400W/m^2 at 1AU (outside the Earth's sheltering fields and such) - and most of that difference is some really nasty, ionizing stuff. To the best of my knowledge, the moon is rather outside the Earth's magnetic shielding influence.

But things will certainly be learned in the process!

Some forms of life can tolerate remarkable levels of ionizing radiation, though I doubt anything terrestrial would survive a pass through Jupiter's radiation belts unshielded.

It has been suggested that some fungi can extract useful energy from radiation: https://www.rsb.org.uk/biologist-features/eating-gamma-radia...

We just have to figure out how to make Tardigrades gigantic and then farm them for meat.

(I feel like this must have been a Futurama plot, and mist have ended poorly)

Riding giant domesticated tardigrades on the moon is the future I want.

"Gi'yup little Tardy! We gotta git these dogies to Copernicus before sundown, and that's only two weeks away!"

The Problem with Popplers

Season 2, Episode 18

https://futurama.fandom.com/wiki/Popplers

Tardigrades can survive extreme conditions like vacuum or radiations only when they are in their "hibernating" state, which is quasi-non-living.

The same is true for a few other kinds of animals, which can enter a special inactive state that can survive desiccation or freezing.

When living normally, no animals can resist such conditions, even if some are much more resistant to radiations than humans.

The most radiation-resistant living beings are some kinds of bacteria, e.g. Deinococcus mentioned by another poster, which have some special mechanisms for continuously repairing the DNA molecules that are damaged by radiation, which allow them to live normally while exposed to radiation.

I don't know the exact levels, but radiation+plants doesn't always equal death. Plant genomes tend to be much larger to animal genomes, and much more copies of specific genes.

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

Clerestory at the north and south poles where the sun shines basically all the time.

Don’t let any light in directly, only reflected light.

I read the complete short stories of Arthur C. Clarke recently and one of the things that really struck me was that several of the early stories (long before NASA) had lunar-native plants growing wild on the Moon. For a hard SF writer I found that extraordinary; you forget just how much the speculative consensus has changed within quite a short period.

In a similar vein, several of the early stories seem convinced by the evidence for psionics...

Before the advent of cell phones it seemed expedient to have telepathy for quick communication --- that said, Heinlein did predict them in his novel _Space Cadet_ (though they don't make more than a brief appearance).

For those that don’t understand Clarke’s relation to cell phones:

https://web.mit.edu/m-i-t/science_fiction/jenkins/jenkins_4.....

Clarke had a pretty interesting progression from belief in many paranormal claims to hard core skeptic over his lifetime, and similarly from pantheist to atheist.

Also progression from gay to pedophile.

https://www.thefreelibrary.com/It+doesn%27t+do+any+harm+...m...

There is so much corroborating evidence it's an almost certainty.

Spoiler: this experiment is not going to try to grow plants in the lunar regolith. The "growth chamber" will be a hydroponic set up. The focus will be on the effects of unfiltered sunlight and all the various forms of radiation that are not present on earth because of the atmosphere.

I am curious about how regolith would act as a growing medium.

Plants grow, but not very well.

https://www.nasa.gov/humans-in-space/scientists-grow-plants-...

Note that the article says "A nutrient solution was added daily". The linked paper mentions "MS nutrient solution", meaning <https://en.wikipedia.org/wiki/Murashige_and_Skoog_medium>.

In other words, the regolith served as a challenging substrate, as long as all the necessary nutrients were added. Without those additions, definitely not.

In a lecture I saw 10 years ago, Freeman Dyson advocated for teaching children to genetically engineer plants. He thought without the playful urge of children, we’d never be able to create “warm blooded” plants capable of surviving on asteroids and the moon. He pointed out that there is a greater surface area on the asteroid belt than all the planets.

I still don’t know how he’d deal with atmosphere, but I love the vision. And, I learned that there are some exothermic plants, like Skunk Cabbage, that can chemically regulate their body temperature.

Like I said, I love the vision.

Lots of carbon and oxygen in asteroids if you pick the right ones.

Some of the carbonaceous ones have some nitrogen as well.

The big trick with smelting in space will be capturing all of the dust and smoke instead of losing the stuff and creating navigational hazards.

Hal Clement envisioned a genetically engineered organism able to enclose water in outer space in his short story "Raindrop" --- collected in _Space Lash_ (originally published as _Small Changes_), it is a remarkable collection of short stories, many of which are still relevant today.

> I still don’t know how he’d deal with atmosphere

Rye grass can survive at 0.07 atmosphere [1], or about 1 psi.

Maybe some grid made of periodically anchored cables, covered in thin, transparent, polymer layers?

Stacked layers could be used to limit conducted heat loss, repair urgency, and layer thickness requirement (layers would see pressure difference, probably also important for permiability). At night, pull a thin IR reflective layer over that's some microns thick, that lives out in the zero pressure side, to limit radiated losses.

Once it's all going, maybe some bio plastic synthesis, to make plastics for repairs.

[1] https://ntrs.nasa.gov/citations/19860010460

There are a bunch of challenges to growing stuff on the Moon. The low gravity, the lack of defense from ioizing radiation that we have on Earth and, perhaps most importantly, the day/night cycle.

The Moon is tidally locked with EArth so the da/night cycle is 28 days. Anywhere other than the poles and you'll have ~2 weeks of darkness every month. This affects how you can potentially generate power (ie it complicates solar power generation) but also plant growth. Ideally you want the plants to grow with passive light (ie light from the Sun) because that's "free". So any experiment should try and find out how plants do if they get 14 days of straight sunlight followed by 14 days of straight darkness.

There are some plants you could grow in 14 days of sunlight even if nothing useful can survive the darkness (which, I believe, is unknown). You can spend energy to create light or you can use fiber optic cables to essentially passively pipe light around. I don't know if you can get the right wavelengths you need this way or if it's economically viable.

As for radiation, it's less of an issue for plants but could still be an issue. It's worth finding out. But there are ways you can reduce this. You're going to need something transparent to get sunlight in. You can filter UV rays out to some degree depending on your material. You can even put water between the plants and the sun (ie a water tank between the plants and the Sun).

Or if you can pipe sunlight around fiber optic cables you don't put your plaants on the surface at all. Your pressurize lava tubes instead.

Or if energy becomes so ridiculously cheap that none of these are any problem at all.

Grow them in the lava tubes using mirrors to bounce the light around like the Egyptians used. Sounds like a fun game to be able to place the mirrors around the surface of the moon so that it still has light during the 2 weeks of darkness

I'm curious how feasible it is to put reflectors in orbit around the Moon to create/extend day cycles. I actually found some literature on this [1].

[1]: https://hackaday.com/2024/04/03/space-mirrors-dreams-of-turn...

"This is an idea that’s been around for a hundred years already,"

It's kind of funny to me that "a hundred years ago" has finally gotten to the point that we're still talking technology/industrial age and doesn't seem so old now. When I was a kid, a hundred years ago was still cart & buggy and other low tech things as the most common which made it feel like a really long time ago.

> So any experiment should try and find out how plants do if they get 14 days of straight sunlight followed by 14 days of straight darkness.

I would think the extreme cold would be an even bigger problem than the lack of light.

That's not necessarily a problem. Or at least it's a solvable problem.

A surface greenhouse would be insulated. It would still lose heat to thermal radiation. I'm not sure of the rate. It may be manageable because when the Sun is shining, not only are you heating up but the plants themselves generate heat (ie it's a greenhouse).

This may be another reason why you're better off growing plants underground because it lessens the temperature extremes.

Otherwise things can be heated with waste heat or directly if required.

I'm surprised that they chose 3 pretty complex plants. The duckweed seems like the best idea, but wouldn't it be more useful at this point to be experimenting with more primitive components of an ecosystem rather than full-fledged plants? Like algae and fungus and phytoplankton. It just seems like the question of whether a plant can survive and grow at all on the moon is not that different from whether a human can survive on the moon, and we already know that humans do pretty ok for limited time as long as you keep them in their spacesuits. I guess this is just figuring out what is required for a "plant spacesuit" to start working on extending how long one can last.

I guess it's a top-down vs bottom-up philosophy, or something. I mean, even starting with phytoplankton, we'll have to provide missing nutrients. So it's not like you can just genetically engineer phytoplankton into terraforming the moon on their own. Unless you can figure out how to genetically engineer in a little nuclear reactor so the plants can produce their own missing elements...

Do such kinds of experiments confound our search for extraterrestrial life? Mars and moon missions could introduce tiny life forms, that could be released into the environment. Some of these are extremely hardy (such as tardigrades) which could then start proliferating when conditions are right.

They'd definitely muddy the water, but wouldn't genetics confirm whether a life form is from Earth? (assuming other life even has anything resembling our form of genetics)

No, not least because the panspermia hypothesis says that DNA is in fact not originally from Earth.

Yep! There is very real concern about accidentally introducing Earth life on others moons and planets, and then "discovering" the introduced life instead of actual native life.

As you mentioned with tardigrades, there are life forms and bacteria that could possibly survive a long duration flight through the vacuum of space, then proliferate once it reaches the surface somewhere.

This is usually guarded against by various sterilization techniques applied to the spacecraft before launch, and there is a discipline dedicated to ensuring these events don't happen:

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

Mars, Earth and the Moon are close enough neighbors that rocks which could harbor life are already exchanged between them during impact events.

Life found in deep granite rock on Earth: https://academic.oup.com/femsre/article/20/3-4/399/516507

This recent one even discusses Mars being the origin of life and seeding Earth (panspermia) https://www.sciencedaily.com/releases/2024/10/241003123543.h....

Mars rocks found on Earth: https://www.space.com/mars-meteorites-on-earth-mystery Mars rocks being plausible candidates for harboring life: https://www.planetary.org/articles/nasa-discovers-mars-rock-...

I think reasonable caution by space agencies is wise but it also could have already happened a billion years ago. If we want to survive as a species or lineage of species beyond the Sun enveloping the Earth we will also need to deliberately establish viable life on other planets and even other solar systems at some point, previous historical records of ancestral life or present planetary sterility be damned. Life seems too rare in the universe for it to go down with the ship, we should make an effort to duplicate this experiment even if humanity doesn't make it.

To grow plants anywhere, its important to remember that soil is not required and they can be grown entirely in water. I've done it several times with Kratky method hydroponics and no soil at all.

No plants, just mold or fungus.. It's made of cheese.

Prediction: the plants will do exactly as well as the $7 IKEA plants I compulsively buy and then watch die.

Small side note: if you want your plants to survive, looking up the species and what care it needs can go a long way. Most potted plants don't want direct sunlight and don't want to be close to a source of heat (radiator) or cold (window this time of year). Many plants want to be watered in a specific way and don't want too much of it. That being said, some plants just die, that's the way it is.

People have been growing plants in space stations since 1982. I don't see how growing plants in an isolated greenhouse on Moon would be much different.

https://en.wikipedia.org/wiki/Plants_in_space#Space_station_...

> The response of plants to microgravity on the International Space Station is known, but “we know … almost nothing about how they and other organisms respond to partial gravity,” she says.

> How they will respond to intense lunar radiation is perhaps the biggest question currently—the International Space Station orbits within the Earth’s magnetic field, and so it is exposed to much lower radiation levels than the lunar surface

Has the moon been verified as sterile? Might be good to be sure of that before introducing life to it.

we have bring plant to the moon

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