November 8, 2023

Caroline Cronin

8th Grade

Frost Middle School

Introduction

In the 1960s and 1970s, during the days of Apollo 11, 12, and 17, the first samples of lunar soil were collected from different parts of the moon. After being stored for some 50 years at NASA’s archives in the Johnson Space Center, never exposed to air or water, they were taken out. Scientists at NASA made amazing discoveries that will continue to foster research and help mankind survive longer on the moon in the future. They successfully grew plants in lunar soil. 

But How?

To understand how this happened, we must first examine lunar soil, better known as regolith, and how it’s possible to grow plants in it. The main thing that sets lunar soil apart from Earth soil is its composition. It has a rough texture, with many tiny fragments and minuscule pieces of glass from the collision of meteorites. However, it still shares some of the same elements as Earth's soil such as iron and magnesium. 

To go more in-depth, three other main components make up the regolith: agglutinates, spherules, and lithic elements. Agglutinates are aggregates that are held together with glass and make up about 70% of the regolith. They are created when the impact of micrometeorites melts some of the soil. They range in size - from millimeters to sub-micron, according to Nasa.gov. Spherules are shaped as spheres and also formed on impact when lava is tossed up and cooled when it hits the ground. They are also found in many different sizes, just like agglutinates. Something unique about both agglutinates and spherules is that what they’re made of depends on what element/material has melted them. Finally, lithic elements of lunar soil are large parts of regolith that have rock chips and are less common when they have been broken down. 

How Plants Grew in Lunar Soil/Regolith

If regolith is so different from Earth's soil, then how did plants manage to grow and thrive? This is what scientists at the University of Florida discovered, as they picked up research that began in the times of Apollo. The scientists used Arabidopsis thaliana, or thale cress, to test and study the lunar soil. Using small amounts of regolith, the seeds were planted and watered daily, along with the addition of supplemental nutrients. Two days later, the seeds being tested unexpectedly sprouted. They were healthy and green as normal for four more days. However, from day six and forward, the plants each started doing their own thing. Their growth slowed and some turned red, while others had undersized roots and leaves. 

So, What Happened?

Lunar soil differs greatly from Earth soil, so the plants simply did not have enough time to adapt during this experiment. At the 20-day mark, the scientists gathered the plant’s RNA, which is almost the equivalent of our DNA. The results varied. While it did prove that the plants reacted because of the stress of trying to grow in harsh soil, the lunar soil from Apollo 11 did not foster as much growth as the regolith from Apollo 12 and 17. According to the Washington Post, the plants grown were edible, but not classified as a food crop. 

What This Means for the Future

As the Earth continues to adapt because of climate change, it will become less sustainable. However, there is still hope. The discovery of regolith has opened new doors for the future and many questions have risen. Will plants be able to grow normally in lunar soil? Could the moon sustain plant life? As research continues and technology keeps advancing, someday we will understand the full science of lunar soil.