The Chandrayaan-3 rover currently charting the Moon’s south pole has identified elements indicating the region’s unique composition.
Using its Alpha Particle X-ray Spectrometer (APXS), the rover has identified a mix of elements known to be present in lunar regolith, including oxygen, silicon, aluminium, calcium, iron and titanium. Together, these constitute 99% of the Moon’s loose, rocky soil.
But other elements have been found too. Manganese is one of the rarer elements known among the remaining 1% of the Moon’s soil.
And, now, the Chandrayaan-3 rover’s onboard instruments have identified the presence of chromium and sulphur.
To do so, the rover’s Laser-Induced Breakdown Spectroscopy (LIBS) instrument exposed its regolith samples to high-intensity laser pulses. These energetic pulses concentrate on the sample’s surface, turning it into hot plasma. Elements within this plasma emit unique wavelengths of light, which LIBS analyses.
Samples were also subject to high-intensity rays emitted by the Alpha Particle X-Ray Spectrometer (APXS). Once exposed to alpha particles and X-rays, elements within the sample emit their own unique X-ray signatures, which are measured to identify the substances present. Both instruments identified the presence of sulphur, while chromium was only distinguished by LIBS.
While both have been previously encountered on the lunar surface, they constitute such small amounts in the soil that their discovery at the bottom of the Moon is noteworthy. The presence of sulphur is used as an indicator of volcanic activity on Earth and throughout the solar system. Chinese studies recently shed light on historic lava flows on the Moon’s surface.
Chandrayaan-3 has yet to find hydrogen at the lunar south pole. This is one of the mission’s primary objectives, as well as the hunt for water which together could potentially serve the needs of future crewed Moon landings.
India recently became the fourth nation to successfully land a vehicle on the Moon and the first to do so at the unexplored southern pole.