Characteristics of the lunar samples returned by the Chang'E-5 mission

The CE-5 sample is consistent with weathered mare basalts in mineralogy and petrochemistry, and is classified as low-Ti/low-Al/low-K type with lower REE (rare earth element) contents than KREEP (potassium, rare earth element, and phosphorus). This new sample characterized by high FeO and low Mg index could represent a new lunar basalt. Forty-five years after the Apollo and Luna missions returned lunar samples, China's Chang'E-5 (CE-5) mission collected new samples from the mid-latitude region in the northeastern Oceanus Procellarum of the Moon. Our study shows that 95% of CE-5 lunar soil sizes are found to be within the range of 1.40-9.35 mu m, while 95% of the soils by mass are within the size range of 4.84-432.27 mu m. The bulk density, true density and specific surface area of CE-5 soils are 1.2387 g/cm(3), 3.1952 g/cm(3) and 0.56 m(2)/g, respectively. Fragments from the CE-5 regolith are classified into igneous clasts (mostly basalt), agglutinate and glass. A few breccias were also found. The minerals and compositions of CE-5 soils are consistent with mare basalts and can be classified as low-Ti/low-Al/low-K type with lower rare-earth-element contents than materials rich in potassium, rare earth element and phosphorus. CE-5 soils have high FeO and low Mg index, which could represent a new class of basalt.

Automated summary

The CE-5 lunar sample collected by China's Chang'E-5 mission is consistent with weathered mare basalts in terms of mineralogy and petrochemistry. It is classified as a low-Ti/low-Al/low-K type with lower rare-earth-element (REE) contents compared to KREEP. This new sample, characterized by high FeO and low Mg index, could potentially represent a new class of lunar basalt.