In a groundbreaking discovery that challenges long-held scientific beliefs, researchers have confirmed the presence of iron oxide - commonly known as rust - in soil samples collected from the Moon's surface.
Revolutionary Findings from Lunar Samples
The remarkable discovery comes from analysis of soil brought back by China's Chang'e-6 mission in June 2024. Scientists identified tiny grains of the iron oxide mineral hematite within lunar soil samples, marking the first conclusive evidence of such strongly oxidised minerals on the Moon.
Until now, the Moon had been considered an environment where iron oxidation couldn't occur, with previous studies finding iron primarily in its reduced forms without oxygen attachment. This new evidence fundamentally challenges our understanding of lunar chemistry and surface conditions.
The Meteorite Impact Connection
Researchers theorise that these iron oxides formed during large-scale meteorite impacts in regions similar to the South Pole-Aitken basin and the Apollo crater on the Moon's far side. The intense heat and pressure generated by these cosmic collisions created unique conditions for oxidation processes previously thought impossible on the lunar surface.
According to the study published in Science Advances, the hematite grains were found mainly in special Moon rocks composed of fragments fused together by meteorite impact forces. During these violent events, oxygen-rich minerals like troilite and other sulphides released their oxygen into the immediate environment, which then reacted with iron minerals to create the surprising 'rust' effect.
Implications for Lunar Science
This discovery provides credible evidence for the presence of Fe2O3 on the lunar surface and may help explain mysterious magnetic anomalies detected in the northwestern South Pole-Aitken Basin. These magnetic properties have puzzled scientists for decades and remain poorly understood despite extensive research.
The successful return of soil samples from the SPA Basin by the 2024 Chang'e-6 mission provided the crucial opportunity to search for highly oxidised substances that had eluded detection in earlier missions, including NASA's Apollo program samples.
While the previous Chang'e-5 mission had hinted at localised metal oxidation processes driven by external meteorite impacts, the Chang'e-6 findings deliver the first conclusive mineral evidence for strongly oxidising minerals like hematite existing on the Moon.
This research not only rewrites our understanding of lunar surface chemistry but opens new avenues for investigating the Moon's geological history and magnetic properties, potentially influencing future lunar exploration missions and resource utilisation strategies.
