Today, the "China Aerospace" public account stated that recently, our country's scientific research team analyzed the lunar samples from the South Pole-Aitken Basin on the far side of the moon recovered by Chang'e-6.A major breakthrough in lunar scientific research was achieved - the first discovery of micron-sized hematite (α-Fe2O3) and maghemite (γ-Fe2O3) crystals caused by large-scale impact events.
This discovery reveals a new lunar oxidation reaction mechanism and provides sample evidence for the impact cause of the magnetic anomaly surrounding the South Pole-Aitken Basin.
The results have been published in the international comprehensive journal "Science Advances", which will provide important scientific basis for subsequent lunar scientific research and deepen the understanding of the evolution history of the moon.
According to reports, research suggests that the formation of hematite may be closely related to large impact events in the history of the moon.
The left picture is a high-angle annular dark field image (HAADF) of hematite grains taken using a transmission electron microscope (TEM). The right picture is the contact relationship between iron oxide (oxygen element, magenta) particles and troilite (sulfur element, cyan) particles distinguished using two characteristic elements.
While the large-scale impact formed an instantaneous gas phase environment with high oxygen fugacity, iron elements were oxidized in the high oxygen fugacity environment, causing the desulfurization reaction of troilite, and micron-sized crystalline hematite particles were formed through the gas phase deposition process.
It is worth noting thatThe intermediate products of this reaction are magnetic magnetite and maghemite, which may be the mineral carriers of magnetic anomalies at the edge of the Antarctic-Aitken basin.
This study used samples for the first time to confirm the presence of highly oxidizing substances such as hematite on the lunar surface under a super-reducing background, revealing the oxidation-reduction state of the moon and the causes of magnetic anomalies.
It is understood that the Antarctic-Aitken basin where Chang'e 6 landed is the largest and oldest known impact basin on rocky bodies in the solar system. The scale of the impact when it was formed far exceeded other areas of the moon, providing a unique scenario for exploring special geological processes.
In 2024, the Chang'e-6 mission successfully retrieved lunar samples from the interior of the Antarctic-Aitken Basin, creating the prerequisite for this breakthrough discovery.
