studiot Posted May 13, 2022 Posted May 13, 2022 Quote https://www.bbc.co.uk/news/science-environment-61434295 Scientists have grown plants in lunar soil for the first time, an important step towards making long-term stays on the moon possible. Researchers used small samples of dust collected during the 1969-1972 Apollo missions to grow a type of cress. Much to their surprise, the seeds sprouted after two days. "I can't tell you how astonished we were," said Anna-Lisa Paul, a University of Florida professor who co-authored a paper on the findings. "Every plant - whether in a lunar sample or in a control - looked the same up until about day six." After that, differences emerged. The plants grown in moon soil started to show stress, developed more slowly and ended up stunted. But those involved say it is a breakthrough - and one that has earthly implications. 1
Genady Posted May 13, 2022 Posted May 13, 2022 So, up until about day six the plants used nutrients and organic matter stored in the seeds, and used the soil just to hold to something. After that, the plants needed more from the substrate and then "discovered" that something is missing. I'd guess that botanists know what is missing. I read this news and couldn't understand what was so astonishing, what did they expect, what new knowledge have they obtained... 2
Sensei Posted May 13, 2022 Posted May 13, 2022 (edited) 1 hour ago, Genady said: After that, the plants needed more from the substrate and then "discovered" that something is missing. I'd guess that botanists know what is missing. https://www.google.com/search?q=moon+soil+chemical+composition Nitrogen is not on the list of elements.. "The bulk chemical composition of lunar dust varies across the lunar surface, but is about 50% SiO2, 15% Al2O3, 10% CaO, 10% MgO, 5% TiO2 and 5-15% iron (Table 1), with lesser amounts of sodium, potassium, chromium, zirconium." On Earth, nitrogen compounds found in soil are produced during lightning strikes and by nitrogen-fixing microorganisms. Edited May 13, 2022 by Sensei 1
joigus Posted May 13, 2022 Posted May 13, 2022 As @Sensei said, regolith is not a true soil. Google: "why is regolith not a true soil" https://en.wikipedia.org/wiki/Regolith Even on Earth, where molecular nitrogen is very abundant in the atmosphere, we need nitrogen-fixing bacteria. Only physical processes and few and very special organisms can break the N2 triple bond. I suppose @Genady's picture is correct that, once the nutrients from the seeds run out, the plant cells simply didn't find the nitrogen to synthesize their proteins and nucleic acids. I would assume lunar regolith is poor in phosphorus too, but I'm not sure. Interesting news. 1
zapatos Posted May 13, 2022 Posted May 13, 2022 2 hours ago, Genady said: I read this news and couldn't understand what was so astonishing, what did they expect, what new knowledge have they obtained... It struck me the same way. Back in 4th grade we sprouted seeds on wet paper towels. They also started to look bad after a while. 1
Danijel Gorupec Posted May 13, 2022 Posted May 13, 2022 I did not understand if they added water to the soil or not? (btw, I would be more interested about an experiment to check if lithoautotrops can live there - but I guess it could take a long time to check it) 1
studiot Posted May 13, 2022 Author Posted May 13, 2022 Thanks for the valuable comments on aspects I had not considered. That is what a discussion site is for. 🙂
joigus Posted May 13, 2022 Posted May 13, 2022 1 hour ago, Danijel Gorupec said: I did not understand if they added water to the soil or not? (btw, I would be more interested about an experiment to check if lithoautotrops can live there - but I guess it could take a long time to check it) Brilliant point. I hadn't thought about it.
John Cuthber Posted May 13, 2022 Posted May 13, 2022 According to this, you should be able to find "moon dust" with enough potash to grow plants. But without combined nitrogen you are stuffed. https://sites.wustl.edu/meteoritesite/items/the-chemical-composition-of-lunar-soil/ 1
zapatos Posted May 13, 2022 Posted May 13, 2022 1 hour ago, Danijel Gorupec said: I did not understand if they added water to the soil or not? (btw, I would be more interested about an experiment to check if lithoautotrops can live there - but I guess it could take a long time to check it) AFAIK, seeds will not germinate without water (along with the right temperature and sometimes other factors).
Sensei Posted May 13, 2022 Posted May 13, 2022 (edited) Plants (with seeds, which they tried) are multicellular organisms. They (i.e. scientists working on this project) should be successful with unicellular organisms first (e.g. air nitrogen-fixing ones?), and then try with multicellular ones because they are more challenging. Then check the cooperation between the nitrogen-fixing unicellular microorganisms and the multicellular ones, which will use nitrogen compounds created for them. Edited May 13, 2022 by Sensei
Ken Fabian Posted May 16, 2022 Posted May 16, 2022 A breakdown of the available nutrients seems appropriate; as others point out getting seeds to sprout is not indicative of an adequate growing medium. About the best it does is indicate an absence of toxicity to plants, or was the "soil" washed or otherwise modified? Mars "soil" would definitely need to have the perchlorates washed out as a preparatory step. NPK are just the big ones where plant nutrients are concerned and for a great many plants the presence of soil biota is critical, including for making usable nutrients from raw rock and mineral material. But I am not convinced this kind of experiment has much value and suspect it is more about keeping the hype about desirability and inevitability of human occupation alive; being able to grow plants in Moon or Mars "soil", when suitable soil, with it's mineral abundances and mineral absences is just one of a great many requirements for viable agriculture will give a misleading impression - almost inconsequential compared to some of the difficulties. On Earth the kinds of construction costs of suitable habitat like the moon needs would send farmers broke before they ever planted anything. And doing it here would be much easier and less costly. Economics is not inconsequential - if providing basic needs takes more economic resources than what the available labour can produce the enterprise will fail; some very big payoff is needed to justify Earth's subsidies.
Endy0816 Posted May 16, 2022 Posted May 16, 2022 (edited) 2 hours ago, Ken Fabian said: A breakdown of the available nutrients seems appropriate; as others point out getting seeds to sprout is not indicative of an adequate growing medium. About the best it does is indicate an absence of toxicity to plants, or was the "soil" washed or otherwise modified? Mars "soil" would definitely need to have the perchlorates washed out as a preparatory step. NPK are just the big ones where plant nutrients are concerned and for a great many plants the presence of soil biota is critical, including for making usable nutrients from raw rock and mineral material. But I am not convinced this kind of experiment has much value and suspect it is more about keeping the hype about desirability and inevitability of human occupation alive; being able to grow plants in Moon or Mars "soil", when suitable soil, with it's mineral abundances and mineral absences is just one of a great many requirements for viable agriculture will give a misleading impression - almost inconsequential compared to some of the difficulties. On Earth the kinds of construction costs of suitable habitat like the moon needs would send farmers broke before they ever planted anything. And doing it here would be much easier and less costly. Economics is not inconsequential - if providing basic needs takes more economic resources than what the available labour can produce the enterprise will fail; some very big payoff is needed to justify Earth's subsidies. Yeah I'm thinking it'll be mainly hydroponics anyways. Rockwool should be possible to manufacture from local Basalt. Will definitely depend on the relative costs of Imports vs Local production. Edited May 16, 2022 by Endy0816
Prometheus Posted May 23, 2022 Posted May 23, 2022 On 5/13/2022 at 1:21 PM, Genady said: I read this news and couldn't understand what was so astonishing, what did they expect, what new knowledge have they obtained... It was unknown whether the plants would germinate at all - the fact they did tells us that regolith did not interfere with the hormones necessary for this process. The plant they chose was the first one to have its genome sequenced, allowing them to look into the transcriptome to identify epigenetic changes due to the regolith, particularly what stress responses were triggered. They also compared regolith from 3 different lunar sites, allowing them to identify differences in morphology, transcriptomes etc between sites. Full paper here: https://www.nature.com/articles/s42003-022-03334-8 3
studiot Posted May 23, 2022 Author Posted May 23, 2022 1 hour ago, Prometheus said: Full paper here: https://www.nature.com/articles/s42003-022-03334-8 Thanks for the further more detailed information. +1
joigus Posted May 23, 2022 Posted May 23, 2022 1 hour ago, Prometheus said: It was unknown whether the plants would germinate at all - the fact they did tells us that regolith did not interfere with the hormones necessary for this process. The plant they chose was the first one to have its genome sequenced, allowing them to look into the transcriptome to identify epigenetic changes due to the regolith, particularly what stress responses were triggered. They also compared regolith from 3 different lunar sites, allowing them to identify differences in morphology, transcriptomes etc between sites. Full paper here: https://www.nature.com/articles/s42003-022-03334-8 Thanks
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