Sulphur On Moon Confirmed By Another Instrument On Pragyan Rover

The Pragyan rover has previously detected the presence of various elements, such as sulphur and oxygen, on the moon. On Thursday, ISRO confirmed that another instrument on the Pragyan rover has identified sulphur in the southern polar region of the moon using a different method.

The discovery of sulphur in the moon's southern polar region, where Chandrayaan 3 successfully touched down on August 23, using two different techniques, will necessitate scientists to provide an explanation regarding the source of this sulfur. They will need to determine whether it is intrinsic to the moon, volcanic in origin, or derived from meteorites.

The Alpha Particle X-ray Spectrometer (APXS) instrument onboard the Pragyan rover has confirmed the presence of sulphur in the moon's southern polar region, using a different technique than the laser-induced breakdown spectroscopy (LIBS) and thermal emission spectrometer (TES) instruments.

The APXS instrument fires a beam of alpha particles at the lunar surface. When the alpha particles interact with the lunar material, they produce X-rays that are characteristic of the elements present. The APXS instrument can detect a wide range of elements, including sulphur.

The APXS instrument has detected sulphur in the form of sulfates, which are compounds of sulphur and oxygen. The APXS instrument has also detected other minor elements in the region, including chlorine, potassium, and silicon.

Sulphur usually originates from volcanic activities, but the scientific community has not yet shed any light on the confirmed presence of Sulphur on the moon. The earlier technique that detected Sulphur was the Laser-Induced Breakdown Spectroscope onboard the Pragyan rover. Now, the Alpha Particle X-ray Spectroscope (APXS) has also identified Sulphur and some other minor elements.

"This finding by Ch-3 compels scientists to develop fresh explanations for the source of sulfur (S) in the area: intrinsic, volcanic, meteoritic," ISRO tweeted in a recent update on Chandrayaan 3.

Sulphur on the Moon: What Does It Suggest?

Sulphur was not expected to be found in lunar soil. However, the confirmation of sulfur's presence through two rover mechanisms raises questions. Elements such as aluminum, silicon, calcium, and iron were anticipated and have also been found.

"What constitutes the lunar soil and rocks in the south polar region where Chandrayaan-3 landed? How do they differ from other highland regions? These are the inquiries that the Chandrayaan-3 rover aims to address with its scientific instruments," explained ISRO.

How Does the Alpha Particle X-ray Spectrometer (APXS) Work?

The Alpha Particle X-ray Spectrometer is the latest technique that confirmed the presence of sulfur on the moon. According to ISRO, the APXS instrument is ideally suited for in-situ analysis of the elemental composition of soil and rocks on planetary surfaces with minimal atmosphere, such as the Moon. This instrument carries radioactive sources emitting alpha particles and X-rays onto the surface sample. The atoms within the sample subsequently emit characteristic X-ray lines corresponding to the present elements. By analysing the energies and intensities of these characteristic X-rays, researchers can identify the elements present and their relative abundances.