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New Study Reveals Common Presence of Submicroscopic Magnetite on the Moon
A recent study spearheaded by researchers Li Yang and Cao Zhi from the Institute of Geochemistry at the Chinese Academy of Sciences has confirmed the widespread existence of submicroscopic magnetite particles throughout the lunar surface. This discovery significantly enhances our comprehension of the lunar microscale oxidation environment.
The team examined droplet-like, rounded iron-sulfide grains found within impact glasses in the Chang’e-5 lunar soil sample. Through in-situ electron microanalysis, they established that submicroscopic magnetite is a common feature in the lunar regolith, with its prevalence closely linked to the titanium (Ti) content in the analyzed regions.
Magnetite plays a crucial role in planetary science, serving as a marker for paleomagnetic fields and potential biological activity. Traditionally, it has been perceived as a rare mineral on the predominantly reduced surface of the Moon.
While prior studies utilizing Mössbauer spectroscopy and electron spin resonance (ESR) hinted at the existence of magnetite-like phases in Apollo lunar soil samples, there was an absence of mineralogical evidence affirming their origin or distribution across the lunar surface.
In their groundbreaking research, Li and Cao found that the magnetite particles were embedded in the rounded iron-sulfide droplets found in impact glasses. They noted that the amount of magnetite corresponds positively with the Ti content of the glass, suggesting that these particles are products of impact events.
The researchers proposed the eutectoid reaction mechanism (4FeO = Fe3O4 + Fe) as a viable explanation for magnetite formation during these impacts.
Statistical analyses from the study indicated the presence of seven magnetite-bearing iron-sulfide droplets among approximately 200 glassy grains, demonstrating that while the sulfide-droplet-on-glass assemblage is prevalent, there is a discernible probability associated with its formation. The findings emphasize the correlation between magnetite formation and Ti content in the impact glass.
“The submicroscopic magnetite identified within the iron-sulfide grains offers in-situ mineralogical evidence for the magnetite-like phases documented during the Apollo missions,” stated Li Yang. “This supports the hypothesis that impact-induced submicroscopic magnetite may be a widespread feature within the high-Ti regions of lunar regolith.”
The research findings were published in the journal Science Advances on September 20, contributing to the ongoing discussion regarding the nature of impact-induced mineral formations on the Moon.
The implications of this study extend further, bolstering previous claims regarding an impact-origin mechanism behind the magnetic anomalies observed on the lunar surface. Interaction between sulfides in the lunar outer core and ilmenite from early mantle overturning events may have occurred under the high-pressure conditions prevalent at the lunar core-mantle boundary, potentially leading to the dissolution of oxygen in sulfides and subsequent formation of magnetite within the Moon’s depths.
More information: Zhi Cao et al, Submicroscopic magnetite may be ubiquitous in the lunar regolith of the high-Ti region, Science Advances (2024). DOI: 10.1126/sciadv.adn2301
Citation: Submicroscopic magnetite may be ubiquitous in lunar regolith of high-Ti region (2024, September 25) retrieved 26 September 2024 from https://phys.org/news/2024-09-submicroscopic-magnetite-ubiquitous-lunar-regolith.html
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