The first seeds to ever sprout in lunar soil poked their heads above moon dirt at the University of Florida in May. Decades of research and experimentation led to this breakthrough which marks the first time terrestrial plants have grown in extra-terrestial soil. It also offers hope that astronauts will one day be able to grow food on the moon.
Three scientists from the University of Florida filled 12 pots of soil from the space expeditions Apollo 11, 12, and 17; 4 pots for each trip’s sample. They chose to use thale cress, a small flowering weed, due to its ability to grow in small amounts of dirt, which was important because NASA was frugal when providing the samples. Sixteen additional pots were filled with volcanic material from Earth, which is often used to mimic lunar soil. These pots were treated with the same nutrients and light levels to ensure unbiased results. Aside from these pots, there was also a control group of plants grown in soil samples from Earth.
The seeds did sprout, but compared to the control group, seedlings were not nearly as successful. The healthiest plants were smaller than they should have been, while the weakest were smaller still and had a sickly purple tint, a sign of plant stress. This is most likely due to the sharpness of the soil, caused by high amounts of metallic iron (compared to the oxidized iron in the Earth’s soil), and glass shards formed by lunar surface collisions. The soil also lacked many nutrients that plants require to grow such as phosphorus, nitrogen, and potassium.
Because the soil from the Apollo 11 samples had been on the moon’s surface the longest, it had significantly more glass and metallic iron than other samples, causing the Apollo 11 thale cress plants to be the smallest and least healthy of all the plants grown.
Altogether, the project was considered a success and proved that plants can grow in lunar soil. However, they were nowhere close to proving that lunar soil was viable for growing other plants that need more specific conditions, like vegetables or fruits. The University of Florida scientists believe that there are many solutions to the poor growth including genetic engineering and using younger or modified soil.
[Source: Science News; Image Credit: Tyler Jones]