Scientists have grown seeds in lunar soil for the first time, using materials salvaged from NASA flights in 1969 and 1972. This breakthrough heralds the prospect of using Earth’s flora to support human colonies on distant worlds.
Researchers said they sowed seeds of Arabidopsis thaliana, a small flowering herb, in 12 small thimble-sized containers each containing one gram of lunar soil, or lunar regolith, and watched them germinate and push Thursday. Because lunar regolith differs significantly from Earth soil in terms of sharp particles and lack of organic content, it was unclear whether the seeds would germinate.
Horticultural science professor Anna-Lisa Paul said it took their breath away when they first witnessed the number of green shoots spurting across all the samples. Paul added that in lunar regolith, plants can grow. This simple remark opens the door to future exploration using resources already in place on the Moon and, most likely, Mars. Each seed germinated and there was no visible difference between seeds planted in regolith – largely crushed basalt rocks – and seeds sown in volcanic ash from Earth with a mineral content and size of particles identical to the first phases of growth.
Not surprisingly, regolith seeds performed less well than comparison plants. They grew more slowly and were generally smaller, had more stunted roots, and were more likely to exhibit stress-related characteristics like smaller leaves and dark red-black coloring that was not typical of healthy growth. They also demonstrated stress-related gene activity similar to plant responses to salt, metal, and oxidation.
In three days, the seeds germinated. The researchers picked all but one of the plants from each container after about a week of cultivation. This was allowed to grow for 20 days before its leaves were removed to test gene activity. The researchers also found that regolith on the lunar surface that had been exposed to cosmic rays and the solar wind for extended periods was less conducive to growth.