Two years ago, China's Chang'e-5 lander touched down on the Moon, returning the first lunar samples to Earth since the Apollo era. On-site analysis of nearby reflectance spectra confirmed water presence at an average of 120 parts per million—a groundbreaking first.
China's lunar exploration program has successfully deployed multiple landers and rovers. The Chang'e-5 mission stood out as the most ambitious, mirroring the Apollo program's sample-return objective from over 50 years ago.
The lander touched down north of Oceanus Procellarum, one of the Moon's youngest volcanic regions, before delivering nearly two kilograms of lunar rocks to Earth weeks later.
Beyond sample collection, onboard instruments analyzed the surrounding regolith. Spectroscopic imaging revealed water molecules in the lunar soil. These findings are detailed in Science Advances.
While orbital missions and returned samples have long indicated water on the Moon, this marks the first direct in-situ detection. Chang'e-5's Lunar Mineralogical Spectrometer measured concentrations averaging 120 parts per million in northern Oceanus Procellarum.
Notably, a nearby rock showed higher levels, up to 180 parts per million. This porous, cavity-riddled specimen likely originated from subsurface volcanism, hinting at deeper water sources beyond surface regolith minerals.
Further research is essential, but this discovery implies that volcanic deposits could support sustained human presence at lower lunar latitudes, where ice is scarce.
NASA is poised for similar in-situ water probes. The VIPER rover targets the lunar south pole by 2024 to map ice in near real-time, while Astrobotic's rover will scout water traces there earlier for NASA.
