Lunar soil from the moon's far side is sticky due to tiny, irregular particles with high feldspar content and space weathering effects.

Chinese scientists have explained why lunar soil from the moon’s far side, collected by the Chang’e-6 mission, is unusually sticky and clumpy. Research published in Nature Astronomy found the soil’s cohesion stems from extremely fine, irregularly shaped particles—especially those below 100 micrometers—due to high feldspar content and intense space weathering. Weak forces like Van der Waals and electrostatic interactions, amplified by particle shape and friction, cause the soil to form steep piles. The samples, from the South Pole-Aitken Basin, had a D60 of 48.4 micrometers and totaled 1,935.3 grams. The findings are critical for future lunar missions involving construction and equipment operation.