Lunar vortices are mysterious, light-colored, winding structures on the lunar surface that extend for hundreds of kilometers.
These intriguing patterns, visible even from a backyard telescope, have for years defied a simple explanation. Recent research suggests that the swirls may be magnetized by invisible magmas beneath the moon’s surface.
New insights into lunar vortices
Recent modeling and space data indicate that rocks in the lunar vortices become magnetized, which deflects or redirects solar wind particles that are constantly bombarding the moon. This redirection causes nearby rocks to darken due to chemical reactions from the collisions, while the vortices themselves remain light-colored.
Michael J. Krawczynski, an associate professor at Washington University in St. Louis, explains, “Impacts can create these kinds of magnetic anomalies. But there are vortices where we just don’t know for sure how an impact can create that shape and that size of something.” This observation points to a more complex process behind the formation of the vortices, suggesting that surface impacts alone cannot be responsible for their unique shapes and sizes.
Krawczynski and his team propose that underground lava cools slowly in a magnetic field could be responsible for the magnetic anomalies observed in the eddies. Their experiments, published in the Journal of Geophysical Research: Planets, focused on the mineral ilmenite, which is abundant on the moon.
They discovered that under lunar conditions, ilmenite can react to form magnetizable iron metal particles, potentially explaining the magnetization of the vortices. Yuanyuan Liang, a co-author of the study, noted, “The smaller grains we worked with seemed to create stronger magnetic fields because the surface area to volume ratio is larger for the smaller grains compared to the larger grains. With more exposed surface area, it is easier for the smaller grains to undergo the reduction reaction.” This finding suggests that the size and distribution of mineral grains play a crucial role in the magnetization process.
Implications for lunar exploration
Determining the origin of lunar vortices is crucial to understanding the processes that shaped the lunar surface and the history of the moon’s magnetic field. Future missions, such as NASA’s planned 2025 rover mission to the Reiner Gamma Vortex, will help gather more data to confirm these findings. “If you’re going to make magnetic anomalies using the methods we describe, then the subsurface magma has to contain a lot of titanium,” Krawczynski said. “We’ve seen evidence that this reaction creates iron metal in lunar meteorites and in Apollo lunar samples.
But all those samples are surface samples lava flowsand our research shows that subsurface cooling should significantly enhance these metal-forming reactions.” This insight could transform our understanding of the moon’s geology and the role of magnetic fields in shaping planetary surfaces.
This research will help interpret data from future lunar missions, particularly those investigating magnetic anomalies. For now, Krawczynski emphasizes the need for more direct sampling: “If we could just drill down, we could see if this reaction was happening. That would be great, but it’s not possible yet. Right now, we’re stuck on the surface.” As technology advances, future missions could eventually offer the ability to drill beneath the lunar surface, which could provide a more comprehensive understanding of these puzzling features.
The findings from these studies will be crucial if NASA and other space agencies are preparing for upcoming lunar missions, aiming to unravel the mysteries of lunar vortices and their implications for the geological history of the moon. By understanding the magnetization process and the role of subsurface magma, scientists hope to gain new insights into the moon’s past and evolution. This research not only sheds light on lunar phenomena, but also improves our broader understanding of planetary magnetism and geological processes in our solar system.
