Scientists Just Proved That Plants Can Grow in Lunar Soil | Unveiled

Scientists Just Proved That Plants Grow in Lunar Soil

In July 1969 humans landed on the moon, marking the first time that our species had ever visited a celestial body other than Earth. But, in the decades since, it can feel as though the lunar program hasn’t hugely advanced. We’ve sent landers and orbiters, robots and AI, yes… but the human missions are again a faraway dream. Despite this, though, NASA and other space agencies are still seriously considering permanent human settlements on the moon, and also Mars. So, this latest breakthrough is a major step toward that.

This is Unveiled, and today we’re exploring how scientists have proven that plants can grow in lunar soil.

As far as we know so far, Earth is the only planet in the universe with plants living on it. And here, plants play an extremely important role. They produce oxygen for many animals to breathe; they’re the main food source for herbivores; they help clean the air, regulate the water cycle, and more. In short, plant life is essential for other life on Earth. But plants also rely on this planet’s natural conditions to sustain themselves. Typically, five conditions need to be met in order for plants to grow: there needs to be sufficient light, water, air, nutrients, and space. Of course, with the sheer variety in the plant world, all five don’t necessarily apply to all... and some can grow without sunlight, for example, while others can go without air. But still, as a general rule, these five things are needed… and, within that, soil is crucial. Plants depend on the rich support that dirt provides, with the soil they’re bedded in supplying water, oxygen, and essential nutrients for successful growth. And so, with food crops specifically, the soil used directly impacts the quality of the food grown. Which is a potentially major problem when we look to other planets and moons.

Scientists have never tried to grow plants in Martian soil before, as we’ve never been able to bring back a sample of Red Planet dirt. This could soon change, following the Mars Sample-Return Mission, a proposed future lander which is aiming to bring a bit of Mars back home… but for now, it’s a work in progress. The situation with the moon is different, though, and a little more promising… because we do at least have genuine lunar soil to work with. Moon samples were gathered more than fifty years ago, during those iconic Apollo missions. Although it’s not as though we have buckets of the stuff. Lunar soil is extremely limited and getting some to experiment with involves a long and stringent application process. Nevertheless, in May 2022, news broke of a study that did get hold of lunar soil – a few spoonfuls of it – and there followed a spectacular achievement.

Professors Anna-Lisa Paul, Stephen Elardo, and Rob Ferl, of the University of Florida, published their findings in the journal “Communications Biology”. And they had to make those small samples work, so they performed micro-sized experiments. They split the soil – also known as lunar regolith - into equal portions, a gram each, and placed those portions into tiny pots. It was made sure that the soil was pure, before the researchers added nutrients with an eye toward growing something within it. The seed of a thale cress plant was added last of all, and then they waited.

Thale cress was chosen specifically because its genetic code has been fully mapped and therefore it’s easy to work with. Meanwhile, for a control sample, the same seeds were added to volcanic ash because it’s one of the closest things on Earth we have to lunar soil. All samples were left alone for two days, after which they were checked… and researchers were stunned. The plants had sprouted in the volcanic ash, which wasn’t too surprising, but there were also shoots in the lunar regolith collected from the moon. The experiment had, for the first time ever, proved that it is indeed possible to make the moon’s mix of dust and rock fertile enough to grow life. By just adding a series of nutrients to it, our understanding of the environment of the moon had been changed forever.

Naturally, these findings have enormous implications for future space missions and manned crews. Now, the moon appears just that little bit more habitable. There are still many other potential problems to counter, but we have at least apparently found an answer to the soil. And, what’s more, if there’s nothing inherently special about lunar regolith, then there’s perhaps reason to think the soil on other moons and planets could be made fertile in a similar way, as well. However, even at this early stage, it doesn’t appear quite so simple as all that.

For one, there were reported differences in how well the thale cress grew, depending on where and when the lunar soil was gathered. The samples used within the study had originally been taken from three different areas of the moon and on three different missions - Apollos 11, 12, and 17. Each varied in what the researchers called “maturity”, referring to how long it had been exposed to the radiation of space and cosmic wind. It was found that the less mature the lunar soil was, the better the plants grew. But, truth be told, even those “better” plants had difficulty – displaying slow growth, small size, and shorter roots. There was certainly life there, and after just two days, but it had been a struggle.

To better examine exactly what their plants experienced, those behind the study harvested each after multiple weeks of growth and checked their genetic code. This revealed that the plants had indeed found the lunar soil stressful and challenging, with the data revealing similarities to what might be seen were a plant to be placed in soil with high amounts of heavy metals here on Earth. In real time, the first signs of this stress only started showing on the plants after six days, or so… but, unfortunately, it had been ever present. Another problem that was apparent throughout, however, was watering. It turns out that lunar regolith actively repels water, causing it to bead up, to kind of congeal on top, when poured. The soil had to be forcibly mixed in with the water, then, for it to take hold.

But, of course, whatever the details, the result of “plants grown from moon soil” can be seen as a rousing success. And, even with the difficulties, this kind of information is exactly why researchers perform these experiments. We now know, for instance, that one of the problems we’ll encounter if we ever try to start agriculture on the moon is the soil’s resistance to water… and so, we’ll have to develop a tool or system to deal with that. Because the bottom line is that no matter where we go in space, if we plan on living there then we’ll need to be able to grow there – for sustainable food, to build a friendly environment, and even for the creation of things like medicine or textiles.

NASA’s Artemis Program has long been in the pipeline, but if (and when) it does get off the ground, perhaps it will be the stage on which we’ll trial lunar growth on a mass scale. For now, this growing of thale cress out of thimble-sized lunar samples represents a crucial move forward. The next steps include pinpointing exactly what types of lunar soil work best of all, and exactly where those types can be found. That information will then help to guide future missions (including Artemis) to the best possible landing sites. There’s little doubt that any future, long-term moon mission would rely on food packets sent from Earth, as well… the moon’s relatively close proximity to home is arguably the main reason why all trial runs should take place there first of all, because it is at least possible to send supplies. But, if food could be grown there, and the first developments toward sustainable living achieved, then suddenly more distant missions become slightly more possible. Indeed, in reaction to this soil study, the NASA scientist Sharmila Bhattacharya said that; “Plants are what enable us to be explorers” … and this breakthrough is true testament to that.

For essentially all of human history, the moon has been something of a mystery to us. And, even in the past few decades, when our knowledge about it has significantly grown and accelerated, it’s still always been seen as a barren and lifeless world. Very unlike Earth, and seemingly less and less likely to be somewhere that we should seriously consider for future human outposts. And yet, today, that may have all changed. We’re still a long way away from a fully “green” moon… but life really has now sprung out of its alien dust. And that’s how scientists just proved that plants can grow in lunar soil.