Widespread hydration was detected on the lunar surface through observations of a characteristic absorption feature at 3 µm by three independent spacecraft^1,2,3. Whether the hydration is molecular water (H₂O) or other hydroxyl (OH) compounds is unknown and there are no established methods to distinguish the two using the 3 µm band⁴. However, a fundamental vibration of molecular water produces a spectral signature at 6 µm that is not shared by other hydroxyl compounds⁵. Here, we present observations of the Moon at 6 µm using the NASA/DLR Stratospheric Observatory for Infrared Astronomy (SOFIA). Observations reveal a 6 µm emission feature at high lunar latitudes due to the presence of molecular water on the lunar surface. On the basis of the strength of the 6 µm band, we estimate abundances of about 100 to 400 µg g⁻¹ H₂O. We find that the distribution of water over the small latitude range is a result of local geology and is probably not a global phenomenon. Lastly, we suggest that a majority of the water we detect must be stored within glasses or in voids between grains sheltered from the harsh lunar environment, allowing the water to remain on the lunar surface.

三个独立的航天器^1,2,3通过观察3 µm处的特征吸收特征，在月球表面发现了广泛的水合作用。水化是分子水（H ₂ O）还是其他羟基（OH）化合物是未知的，还没有建立使用3 µm谱带⁴来区分两者的方法。但是，分子水的基本振动会在6 µm处产生光谱特征，而其他羟基化合物则不具备这种特征⁵。在这里，我们使用NASA / DLR平流层红外天文观测台（SOFIA）展示了6 µm的月球观测结果。观测结果表明，由于月球表面存在分子水，因此在高月球纬度处有6 µm的发射特征。上的6微米带的强度的基础上，我们估计约100丰度至400μg克^-1 ħ ₂ O.我们发现，水在小纬度范围的分布是当地的地质的结果，可能是不全球现象。最后，我们建议，我们检测到的大部分水必须存储在玻璃杯中或在恶劣的月球环境庇护下的谷物之间的空隙中，以使水保留在月球表面上。