最新发现！月球上还有“迷你水库”？

月球上有水吗？有的话，它从哪里来？又储存在何处？

过去20年，科学家在月球表面发现了许多存在水的证据。而近日，中国科学家发现了月球上的“迷你水库”，它们以玻璃珠的形式存在。这一发现对探索月球水资源，提取样本，支持探月计划有重大意义。

Chinese scientists have discovered a new water reservoir on the moon in the form of glass beads, which could have major significance for probing the water content of the Earth's only natural satellite and potentially extracting them to support future lunar missions.

据新华社报道，最新一期英国《自然·地球科学》发表的研究论文介绍，中英科研人员从嫦娥五号带回的月球样品中发现，撞击玻璃珠是月表水的重要储存库。这些玻璃珠具备维持月表水循环的能力和潜质。

A study published in the journal Nature Geoscience last week revealed soil samples collected by China's Chang'e-5 lunar probe contained impact glass beads that held water in the form of hydroxyl, a molecule consisting of one oxygen atom and one hydrogen atom. Hydroxyl ion is one of the most common ions found in water.

据中国科学报报道，中国科学院地质与地球物理研究所研究员胡森、南京大学地球科学与工程学院教授惠鹤九等科学家合作发现，撞击玻璃珠可能是月球的“迷你水库”——一吨玻璃珠中平均可含一斤水。

科学家发现在嫦娥五号月球样品中，测量到撞击玻璃珠中的水，发现玻璃珠中的水含量从边缘向中心逐渐递减。科研团队推测，这是太阳风中的氢离子注入撞击玻璃珠，并在其内部扩散、保存下来。

玻璃不是只有人类能够制造，自然界中也会形成玻璃。例如，陨石、小行星撞击月球等天体后，会熔融月表的土壤和岩石，这些熔体溅射出来形成的液滴冷却后，就会形成撞击玻璃珠。

These glass beads are created when meteoroids hit the moon's surface, throwing up hot molten droplets which then cool and turn solid. They function like a sponge, soaking up hydrogen atoms carried by the solar wind to form hydroxyl, thus playing a pivotal role in the water cycle of the lunar surface.

数十亿年来，太空天体撞击带来的“翻耕作用”让月壤中普遍存在撞击玻璃珠（含量约为3~5vol%）。研究者估计，月壤中撞击玻璃珠所承载的水量可达到2700亿吨水。“这远比地球四大洋的水储量低，但相对来说是挺可观的。”胡森说。

While each bead only holds a tiny amount of water, these glass balls are so ubiquitous on the moon researchers estimated lunar soils could store as much as 270 billion metric tons of water. For decades, scientists thought the moon was bone dry until discoveries in recent years revealed its soil could hold water.

"The moon potentially holding 270 billion metric tons of water is quite substantial, though it pales in comparison to the amount of water in the Earth's oceans,"  said Hu Sen, a researcher from the Institute of Geology and Geophysics of the Chinese Academy of Sciences and one of the key scientists behind the study.

此外，随着探测能力的提升，科学家发现越来越多无大气的天体表面可能存在水，例如灶神星、水星等。研究者表示，这项研究对于了解这些行星低纬度地区水的来源和成因有重要启示。

胡森说：“后续更深入的精细研究，例如无大气天体表面水的来源、保存、迁移机制等，对未来深空探测任务原位水资源利用的方案设计和提取策略等都有重要参考价值。”

These findings not only provide insight on the origins, storage, and transportation of water on celestial bodies without atmospheres, but they also may prove helpful for planning and building a sustainable human habitat on these planets, he added.

关于月表水的来源，科学家有很多猜想。例如，太阳风携带的氢离子注入月表矿物，月球早期形成时含水并保留至今，彗星和小行星撞击月球时携带而来。

However, the specific origins of the water on the lunar surface remain a mystery. The study presented several potential sources, including solar wind implantation, the release of trapped gas when the moon was hot and volcanically active, and delivery by comets and asteroids.

综合来源：新华社 中国科学报 中国日报