Re-evaluation of Lunar X-ray observations by Apollo 15 & 16

<p>The Apollo 15 & 16 missions were the first to explore the Lunar surface chemistry by investigating about 10 percent of the Lunar surface using a remote sensing X-ray fluorescence spectrometer experiment. The data obtained has been extensively used to study Lunar formation history and geological evolution. In this work a re-evaluation of the Apollo 15 & 16 X-ray fluorescence experiment is conducted with the aim to obtain up-to-date empirical values for aluminum (Al) and magnesium (Mg) concentrations relative to silicon (Si) of the upper Lunar surface. An up-to-date orbit reconstruction, updated instrument response, and improved intensity ratio calculations are used to obtain new intensity ratio maps.</p>