You probably answered your own question. Humans haven't left Low Earth Orbit since December 7th, 1972! We're just coming up on half century anniversary. What a drear celebration that'll be. I expect there was just relatively little interest in exploring these things in the past when it was clear humans weren't going anywhere.
Now there's China + SpaceX. SpaceX is now already launching humans to LEO and their long since stated goal is Mars. And China is also making rapid and major progress in expanding beyond Earth. And China+Russia have already stated a goal of establishing an ideally international manned moon base.
The future has never looked brighter for manned exploration of the stars, and that's going to impact motivations.
"Paul and Ferl applied three times over the course of 11 years for a chance to work with the lunar regolith."
Sounds like people had the idea a while back but apparently getting even just 12 grams of regolith from the [checks notes] 382kg NASA have is a bit tricky.
(Anyone know why NASA are reluctant to let people have regolith?)
You can only use it once before it gets earth contamination. It's been 50 years an we haven't got anymore. Even though there are missions planned the might lose funding or fail, so who knows when they might get more? Also, science advanced with time, if it's all used up, we wouldn't be able to use future tech to analyze it.
There are way more scientific problems than scientists, funding for science is limited and competitive, NASA requires a review process before handing out soil samples...I could go on.
I find the way the article uses the "lunar soil" misleading. On earth, soil is a complex biological output of an ecosystem of microbes, fungi, worms, etc, obviously none of which exist on the moon. In the paper, the authors are (mostly) careful to describe the lunar material as regolith, e.g. "Soils derived from lunar regolith". Failing to make that distinction implies that the raw material on the moon is much more useful on its own than it really is.
I see. I still find this usage confusing, since in the lunar context it seems to simply refer to grain size (regolith -> soil -> dust), whereas terrestrially, the word "soil" has a much richer connotation.
>Researchers placed seeds in the samples, watered them and then put the trays into a terrarium box, to which they added a nutrient solution daily
I'm no expert but this sounds more like using lunar regolith as a hydroponics growth medium than as a soil. Next they might try compressing the lunar samples into more traditional hydroponic pellets and compare the results.
I do wonder how long you'd need to "Mark Watney" the lunar regolith before it becomes proper soil.
Not really. One step beyond hydroponics, aeroponics is quite neat- no rooting medium used, the roots are exposed to air and kept from drying out with a mist of water and nutrients. It's been used by NASA and commercially as an alternative to hydroponics due to less (different, really) maintenance and supposedly faster, larger yields (more efficient, controlled delivery to the roots presumably).
You’re right that you can support plants in inert mediums if there’s a nutrient supplied in the water. I think the person you responded to was suggesting that the soil without added nutrients wouldn’t do anything, which is probably correct.
Since you’re right about aeroponics, I wonder what the practicality of using moon dust as a medium is. Perhaps it contains some amount of minerals that could be extracted by plants, thereby reducing how much of it we need to ship to the moon? I’m not even sure that’s possible without established microbial and mycelial cultures – do plants extract minerals from dirt on their own?
The experiment results aren’t overtly meaningful here in any case. I thought NASA was so interested in aeroponics partially because of how useless the moon is as a medium for agriculture.
Without microbes or fungi, plants are mostly left to either chemical weathering from water or turning carnivorous (which takes a really really long time).
Aeroponics has the added benefit of being really frugal with your water supply. Most of the water in a hydroponic system is literally just sitting around in a tube, useless.
Also, a leak in an aeroponics system is way less catastrophic in a low-to-no gravity situation.
I think using moon dust as a rooting medium would be helpful for water retention in a pseudo-hydroponic setup, as the surface tension would help keep the water from flowing away from the roots. It certainly beats trying to ship the stuff from earth on a rocket, at the very least.
Very disappointing, i expected to see mature plants, sprouted seeds aren't anything to write about, they'll sprout as long as it's moist and warm. Most disappointing is that the scientists were surprised. Then again, this IS a university in Florida...
It took them over a decade to get just a few grams of regolith for the test. You can't exactly support mature plants in a few grams of soil, particularly "soil" that is expected to perform poorly. Especially if you want to test multiple plants and therefore need to further subdivide the meager amounts of regolith they have.
Proving this basic initial step will open up the avenue for further research with larger amounts of regolith in the hopefully near future.
https://www.nature.com/articles/s42003-022-03334-8
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