In an exciting milestone for lunar scientists around the world, India’s Chandrayaan-3 lander touched down 375 miles (600 km) from the Moon’s south pole on August 23, 2023.
In just under 14 Earth days, Chandrayaan-3 has provided scientists with valuable new data and further inspiration to explore the Moon. And the Indian Space Research Organization has shared these initial results with the world.
Data from the Chandrayaan-3 spacecraft, named Pragyan, which means “wisdom” in Sanskrit, shows that the lunar soil contains expected elements such as iron, titanium, aluminum, and calcium. It also showed an unexpected surprise: sulfur.
Related: India’s Chandrayaan-3 lunar probe Pragyan rolls onto the moon’s surface for the first time
Planetary scientists like me knew that sulfur was present in the Moon’s rocks and soil, but at very low concentrations. These new measurements suggest that higher sulfur concentrations than expected may be present.
Prayan has two instruments that analyze the elemental composition of soil: an alpha particle X-ray spectrometer and a laser-induced breakdown spectrometer (LIBS for short). Both of these instruments measured sulfur in the soil near the landing site.
Sulfur in the soil near the moon’s poles could one day allow astronauts to live on Earth, and these measurements are an example of the science that makes exploration possible.
geology of the moon
There are two main types of rock on the moon’s surface: dark volcanic rocks and bright high-altitude rocks. The difference in brightness between these two of his materials creates the familiar images of the face of the “Moon Man” and the “Rabbit Picking Rice” to the naked eye.
Scientists measuring the composition of the moon’s rocks and soil in labs on Earth have found that material from dark volcanic plains tends to contain more sulfur than material from brighter highlands.
Sulfur primarily comes from volcanic activity. Rocks deep within the Moon contain sulfur, and when these rocks melt, the sulfur becomes part of the magma. When the molten rock approaches the surface, most of the sulfur in the magma becomes a gas and is released along with water vapor and carbon dioxide.
Some of the sulfur remains in the magma and remains in the rock after it cools. This process explains why sulfur is primarily associated with the moon’s dark volcanic rocks.
The measurements of sulfur in soil by Chandrayaan-3 were made for the first time on the lunar surface. The exact sulfur content cannot be determined until data calibration is complete.
Uncalibrated data collected by Pragyan’s LIBS instrument suggest that sulfur concentrations in high-altitude soils near the moon’s poles may be higher than in high-altitude soils from the equator, and possibly higher than in dark volcanic soils. There is.
These first results give planetary scientists like me who study the Moon new insight into how the Moon functions as a geological system. But we still have to wait and see whether the fully calibrated data from the Chandrayaan-3 team supports the rise in sulfur concentrations.
Atmospheric sulfur production
Measuring sulfur is of interest to scientists for at least two reasons. First, these findings indicate that highland soils at the Moon’s poles may have fundamentally different compositions compared to highland soils at the Moon’s equatorial regions. This difference in composition is probably due to differences in environmental conditions between the two regions, namely the lack of direct sunlight in the polar regions.
Second, these results suggest that sulfur is somehow more abundant in polar regions. The sulfur concentrated here may have formed from the moon’s extremely thin atmosphere.
The polar regions of the moon receive less direct sunlight, resulting in extremely cold temperatures compared to other parts of the moon. When surface temperatures drop below -73 degrees Celsius (-99 degrees Fahrenheit), sulfur from the Moon’s atmosphere can collect on the surface in solid form, like frost on a window.
Polar sulfur could also come from ancient volcanic eruptions on the moon’s surface, or from sulfur-bearing meteorites that hit the surface and vaporized.
Moon sulfur as a resource
For long-term space missions, many agencies have considered building some kind of base on the moon. Astronauts and robots can travel from their Antarctic base to collect, process, store, and use naturally occurring materials such as sulfur on the lunar surface. This is a concept called on-site resource utilization.
On-site resource utilization reduces trips back to Earth to obtain supplies, giving you more time and energy to explore. Using sulfur as a resource, astronauts can build sulfur-based solar cells and batteries, mix sulfur-based fertilizers, and make sulfur-based concrete for construction.
In fact, sulfur-based concrete has several advantages compared to the concrete typically used in building projects around the globe.
First, sulfur-based concrete hardens within hours rather than weeks, making it stronger and more wear-resistant. And because the mixture doesn’t require water, astronauts can save precious water for drinking, making breathable oxygen, or making rocket fuel.
Seven missions are currently being conducted on or around the moon, but Pragyan’s new measurements will help planetary scientists study the moon’s geological history, as the moon’s south polar region has not previously been studied from the surface. It will help you understand. It will also allow lunar scientists like me to ask new questions about how the moon formed and evolved.