China discovers gamma iron in lunar samples from Chang’e 6 mission

Analysis of lunar samples collected by China’s Chang’e 6 mission has revealed the presence of gamma iron, a discovery that challenges existing understanding of the Moon’s composition. The mission, which landed on the far side of the Moon on June 1, 2024, successfully returned nearly 2 kg of material to Earth.

According to a study published in PNAS, gamma iron typically only forms at temperatures between 912°C and 1,394°C. Given that lunar temperatures generally fluctuate between -248°C and 121°C, pure iron should exist in its alpha conformation. Researchers hypothesize that the gamma iron was created by an extreme temperature spike, such as a meteorite impact, followed by rapid cooling that “froze” the iron in its high-temperature state. Small amounts of carbon may have also helped stabilize this structure, a process similar to tempering steel.