New research suggests that mysterious swirl patterns on the lunar surface may be linked to subsurface magma activity.
The “lunar vortices“observed on the moon show a spiral pattern created by magnetized rocks that deflect or redirect the waves solar wind particles that constantly bombard the moon. Moon rocks that fall within the lunar vortices remain light-colored, while neighboring rocks that do not — and are therefore affected by charged particles from the sun — appear to undergo a chemical reaction that makes them appear darker, according to a statement from Washington University in St. Louis.
However, given the moon has no classic magnetic field Researchers had to look for another source that could have magnetized the lunar vortices, which can stretch for hundreds of kilometers in some areas, according to images from NASA’s lunar exploration rocket (LRO).
“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,” said Michael J. Krawczynski, a co-author of the study and an associate professor of earth, environmental and planetary sciences at Washington University in St. Louis. said in the statement“Another theory is that there is lava underground, which is slowly cooling in a magnetic field and create the magnetic anomaly.”
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“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,” said Michael J. Krawczynski, a co-author of the study and an associate professor of earth, environmental and planetary sciences at Washington University in St. Louis. said in the statement“Another theory is that there is lava underground, which is slowly cooling in a magnetic field and create the magnetic anomaly.”
Using a mineral called ilmenite, which is abundant on the moon, the researchers wanted to mimic the magnetizing effect. They studied the reaction between ilmenite and different combinations of atmospheric chemistry and magmatic cooling speeds to create particles of iron metal, which can be magnetized.
“Our analog experiments showed that we could create the magnetizable material we needed under lunar conditions. So it is plausible that these vortices are caused by underground magma” Krawczynski said in the statement, noting that the subsurface magma must contain a lot of titanium for the results to be true. “We have seen indications that this reaction creates iron metal in the moon meteorites and in the moon samples of ApolloBut all of these samples are surface lava flows, and our research shows that subsurface cooling should significantly enhance these metal-forming reactions.”
Understanding the origins of lunar vortices provides new insights into the processes that shaped the lunar surface and the history of the moon’s magnetic field. NASA plans to send a rover to a lunar vortex called Reiner Gamma in 2025 as part of the Lunar Vertex Missionallowing researchers to examine these surface features up close.
“If we could just drill deeper, we could see if this reaction was happening,” Krawczynski said in the statement. “That would be great, but it’s not possible yet. Right now, we’re stuck at the surface.”
Their findings were published on May 20 in the Journal of Geophysical Research: Planets.