In situ measurements of planetary surfaces can provide more detailed information about mineralogical composition and elemental distribution than the more commonplace remote sensing. Recently, Santosh Vadawale and colleagues reported early results from the Alpha Particle X-ray Spectrometer (APXS) experiment aboard the Pragyan rover of India’s Chandrayaan-3 mission, with a characterization of the Chandrayaan-3 landing site and what it reveals about lunar history and evolution.

The data were collected from a southern high-latitude region of the Moon that was not previously explored by the other lunar missions, which landed between the equatorial and the mid-latitude regions. Individual elements are identified using the measured fluxes of different X-ray lines, corroborated by X-ray fluorescence remote-sensing observations from the Chandrayaan-1 and Chandrayaan-2 orbiters. The authors are able to constrain the abundance of 12 major and minor elements and several oxides, and find a mixing of ferroan anorthosite and magnesian suite around the landing site, with a very uniform spatial distribution. These observations support the predictions of those lunar magma ocean models that consider a stratified crust with ferroan anorthosite on top of a lower crust dominated by Mg-rich rocks.

与更常见的遥感相比，行星表面的原位测量可以提供有关矿物成分和元素分布的更详细信息。最近，Santosh Vadawale 及其同事报告了印度 Chandrayaan-3 任务的 Pragyan 漫游车上的阿尔法粒子 X 射线光谱仪 (APXS) 实验的早期结果，其中描述了 Chandrayaan-3 着陆点的特征以及它揭示了月球历史和月球历史。进化。

这些数据是从月球南部高纬度地区收集的，此前其他月球任务降落在赤道和中纬度地区之间，从未探索过该地区。使用不同 X 射线线的测量通量来识别各个元素，并通过月船 1 号和月船 2 号轨道飞行器的 X 射线荧光遥感观测得到证实。作者能够限制 12 种主要和次要元素以及几种氧化物的丰度，并发现着陆点周围有铁斜长石和镁质套件的混合，且空间分布非常均匀。这些观测结果支持了月球岩浆海洋模型的预测，该模型考虑了在以富镁岩石为主的下地壳顶部具有含铁斜长石的分层地壳。