The elemental composition of the lunar surface provides insights into mechanisms of the formation and evolution of the Moon^1,2. The chemical composition of lunar regolith have so far been precisely measured using the samples collected by the Apollo, Luna and Chang’e 5 missions, which are from equatorial to mid-latitude regions^3,4; lunar meteorites, whose location of origin on the Moon is unknown^5,6; and the in situ measurement from the Chang’e 3 and Chang’e 4 missions^7,8,9, which are from the mid-latitude regions of the Moon. Here we report the first in situ measurements of the elemental abundances in the lunar southern high-latitude regions by the Alpha Particle X-ray Spectrometer (APXS) experiment¹⁰ aboard the Pragyan rover of India’s Chandrayaan-3 mission. The 23 measurements in the vicinity of the Chandrayaan-3 landing site show that the local lunar terrain in this region is fairly uniform and primarily composed of ferroan anorthosite (FAN), a product of the lunar magma ocean (LMO) crystallization. However, observation of relatively higher magnesium abundance with respect to calcium in APXS measurements suggests the mixing of further mafic material. The compositional uniformity over a few tens of metres around the Chandrayaan-3 landing site provides an excellent ground truth for remote-sensing observations.

月球表面的元素组成提供了对月球形成和演化机制的深入了解^1,2 。迄今为止，已经利用阿波罗、月球和嫦娥五号任务采集的样本精确测量了月球风化层的化学成分，这些样本来自赤道至中纬度地区^3,4 ；月球陨石，其在月球上的起源位置未知^5,6 ；以及来自月球中纬度地区的嫦娥三号和嫦娥四号任务^7、8、9的原位测量。在这里，我们报告了印度 Chandrayaan-3 任务的 Pragyan 漫游车上的阿尔法粒子 X 射线光谱仪 (APXS) 实验¹⁰对月球南部高纬度地区元素丰度的首次原位测量。月船三号着陆点附近的 23 次测量表明，该地区当地的月球地形相当均匀，主要由铁斜长石 (FAN) 组成，FAN 是月球岩浆海洋 (LMO) 结晶的产物。然而，在 APXS 测量中观察到相对于钙而言镁丰度相对较高，这表明进一步混合了镁铁质材料。月船三号着陆点周围几十米范围内的成分均匀性为遥感观测提供了极好的地面实况。