Lunar astronauts could potentially make hummus with moon-grown chickpeas

a purple hued light tints everything pink. the fingers from a hand are seen close up, cradling small leaves on a plant growth.
First chickpea seeds in amended moondust. (Image credit: Courtesy of Jessica Atkin)

Researchers have for the first time grown chickpea seeds in soil similar to that found on the moon, paving the way to reduce dependency on packaged foods during future crewed missions.

"The moon doesn't have soil like Earth does," Jessica Atkin, a graduate student at Texas A&M University who is one of the two co-authors of the new study yet to be peer-reviewed, said in a statement

Unlike the soil on Earth, lunar soil lacks organic matter rich in nutrients and microorganisms whose presence is crucial for plant growth. "This adds to other challenges, such as reduced gravity, radiation and toxic elements."

Successfully growing plants on the moon has tangible benefits. The foremost is that it'd provide a sustainable, nutritious resource for future spacefarers, reducing the need to re-supply packaged foods from Earth — an expensive endeavor which doesn't yet meet the demands of long-term space missions. Furthermore, the moon's thin atmosphere is not suitable for us oxygen-dependent Earthlings, so plants on the moon could also offer a source of breathable air for future astronauts.

Because lunar soil isn't friendly toward Earth-like plants, however, even after adding compost mixtures, Atkin and her colleagues think changing the soil's chemical and physical properties could facilitate the presence of beneficial microorganisms. This spurred the new study.

Yet, there wasn't sufficient moon soil on Earth — brought home by the Apollo missions — for the experiments, so Atkin and her colleagues used "amended moondust," a material engineered from Earth's geological materials to replicate lunar soil, such as its minerals and the size of its characteristic particles. The study team hypothesized that the microscopic interactions between chickpeas, arbuscular mycorrhizal fungi (AMF) and vermicompost (VC) would help plant growth by sequestering toxins from the amended moondust and changing its structure to improve water retention and tolerance toward stress. To test that hypothesis, the team used AMF in varying concentrations of amended moondust and vermicompost mixture.

The study team potted chickpea seeds, chosen for the plant's compact size and resilience toward stress. "They are a great protein source and use less water and nitrogen than other food crops," Atkin said in the same statement. "We used a desi chickpea variety to deal with the space limitations inside a habitat."

For the next four months, the containers were stored in a temperature-controlled grow tent, where researchers moistened the soil with purified water.

On day 13, all seeds had germinated but the plants that eventually sprouted showed chlorophyll deficiency as well as other signs of stress, including dwarfism, loss of leaf area and either reduced shoot branching or lack of it. These could be due to the soil's poor water retention capacity, according to the new study.

At day 13, there were 100% germination rates. Experiments are labeled as in Figure 2. Potting mix (control) shows large leaves and greater branching, whereas plants in lunar regolith simulant mixtures show signs of xenomorphism, with reduced leaf area, reduced amount of leaf growth, and smaller shoot height.  (Image credit: Courtesy of Jessica Atkin)

The chickpeas also required 120 days to mature in the experiment, whereas on Earth they usually take just 100 days. The produced chickpeas "will need to be tested for heavy metal concentrations, and we're going to do that," Atkin told New Scientist.

Despite the limitations, researchers say these early results may offer a way to grow plants in-situ on the moon. After all, the study has led to the first time chickpeas have been grown in moondust, albeit a simulated version.

"The novelty about using vermiculture is that it can all be done in space, whether in a space station or on the moon, reducing the need for resupply missions," Atkin added.

This research is described in a preprint paper posted on biorxiv.

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Sharmila Kuthunur
Space.com contributor

Sharmila is a Seattle-based science journalist. She found her love for astronomy in Carl Sagan's The Pale Blue Dot and has been hooked ever since. She holds an MA in Journalism from Northeastern University and has been a contributing writer for Astronomy Magazine since 2017. Follow her on Twitter at @skuthunur.

  • ChrisA
    All these "how to grow food in space" articles are pointless. OK maybe the science is interesting but in practical terms a human needs about 2000 kilo-calories per day to live. and that works out to about one million Kcal per year, allowing for some waste.

    How many chickpea plants must you grow to get a million calories? OK you don't like Hummus, what about =wheat or rice or tomatoes or potatoes or corn. How many plants must you grow to make a million calories?

    It works out to roughly one football field sized farm per =astronaught. more or less.

    This is not surprising because on Earth out farmland ios MUCH larger than out "city land'. A city on Mars or the Moon would be trivial compared to the farm that feeds the city because every person needs a million Calories per year.

    It gets worse... The part of the plant you eat is not even close to 100%, You need space to recycle the stems and leaves and let them decompose. Worse, you can't use natural sunlight because the thin window that lets in light also lets in radiation that will kill the plants. You need a few meters of rocjk and dirt over the planet to shield them and then grow lamps over you entire farm to allow photosynthesis. The nuclear power for the lights and heaters to keep the plant alive.

    A cheaper solution is to get a glass tube and glow algae inside. The tubes can be dense-packed with lamps and a water pumps circulated the algae to a processing plant where is is made to something a person would want to eat. But still You need to make literally "truckloads" of food for each human.

    The better solution is robots. In time robots can do any task and humans will not be needed in space. Except for tourism. Tourism is the only task a robot can't do for you.

    On Earth and in space, farms will always be MUCH larger than cities.
    Reply
  • motie
    ChrisA said:
    All these "how to grow food in space" articles are pointless. OK maybe the science is interesting but in practical terms a human needs about 2000 kilo-calories per day to live. and that works out to about one million Kcal per year, allowing for some waste.

    How many chickpea plants must you grow to get a million calories? OK you don't like Hummus, what about =wheat or rice or tomatoes or potatoes or corn. How many plants must you grow to make a million calories?

    It works out to roughly one football field sized farm per =astronaught. more or less.

    This is not surprising because on Earth out farmland ios MUCH larger than out "city land'. A city on Mars or the Moon would be trivial compared to the farm that feeds the city because every person needs a million Calories per year.

    It gets worse... The part of the plant you eat is not even close to 100%, You need space to recycle the stems and leaves and let them decompose. Worse, you can't use natural sunlight because the thin window that lets in light also lets in radiation that will kill the plants. You need a few meters of rocjk and dirt over the planet to shield them and then grow lamps over you entire farm to allow photosynthesis. The nuclear power for the lights and heaters to keep the plant alive.

    A cheaper solution is to get a glass tube and glow algae inside. The tubes can be dense-packed with lamps and a water pumps circulated the algae to a processing plant where is is made to something a person would want to eat. But still You need to make literally "truckloads" of food for each human.

    The better solution is robots. In time robots can do any task and humans will not be needed in space. Except for tourism. Tourism is the only task a robot can't do for you.

    On Earth and in space, farms will always be MUCH larger than cities.
    Agreed. If you build a greenhouse on the surface of the moon or Mars, the covering will need to be transparent to visible light (which is what the plants need); it will need to block short wavelengths; it will need to block high-energy particle radiation; it will need to survive a pressure difference of about one atmosphere from inside to outside; it will need to keep the inside at the right temperature while the outside temp is varying by hundreds of degrees. Good luck with that. An underground growing tunnel is probably the only good solution. Then there are the infrastructure requirements (water, energy, etc.).

    On Mars, there is the problem of toxic perchlorates in the soil.

    If you carry seeds on a spaceship to Mars, and it takes six months, will the seeds still be viable? Or will their DNA be fried by radiation? I don't know.

    Mars as a backup planet is a nice thought, but IMO we are not nearly ready to pursue it at present. Meanwhile, robotics and AI are improving fast.
    Reply
  • ChrisA
    motie said:


    Mars as a backup planet is a nice thought, but IMO we are not nearly ready to pursue it at present. Meanwhile, robotics and AI are improving fast.
    "Mars as a backup is not even logical. Let's say there is a disaster scenario on Earth like this: Global warming. is left unchecked and it gets to the point where agriculture is impossible in many places of the world. War breaks out as starving people fight over the remaining water and livable land, this leads to a global six-way nuclear war. Industry and cities are gone and much of the world is radioactive. People are using self-made stone tools and eating bugs and roots. Few people live to be 30 years old. 95% of the human population was killed in the war or the after effects. Pandemics like a resurgence of the Black Death run unchecked. Dead bodies are common with no means to dispose of them. Then as luck would have it an asteroid of the size that killed dinosaurs impacts the Earth and makes things even worse.

    The above scenario is not good. But even if it all came to be, the Earth would still be like paradise compared to Mars. On Earth at least there is air pressure and liquid water and a magnetic field and to survive all you need is stone-age technology. On Mars without advanced 22nd-century technology, you'd be dead in seconds.

    Or to say it differently, if you could build an underground city and underground farms on Mars all powered by Fusion energy and maintain artificial closed ecosystems on Mars. Then with far less effort, you could do all of those things on Earth. In fact you would have to. Who would build such things on Mars without first testing the technology on Earth?

    I think Mars and the Moon will be like Antarctica, places where some scientists go to and live for some time then come home and a place where rich tourists can go. We don't build cities in Antarctica because no one really wants to live there forever and it's too expensive.

    Again, it is hard to think of a way that Earth could ever be a worse place to live than Mars and if it does happen then whatever technology you would use to live on Mars could be used on Earth.
    Reply