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Pragyan rover finds sulphur on Moon. IIT professor, part of mission, explains how

Pragyan rover finds sulphur on Moon. IIT professor, part of mission, explains how

  • 1st Sep 2023
  • India Today

An IIT Madras professor who helped with Isro's Chandrayaan-3 mission explained how the Pragyan rover was able to detect sulphur on the Moon's surface.

The Chandrayaan-3's Pragyan rover has detected the presence of sulphur and oxygen on the Moon's surface using Laser Induced Breakdown Spectroscopy (LIBS).

This discovery was part of a joint project between the Indian Space Research Organisation's (Isro) Laboratory for Electro-Optics Systems (LEOS) and the Indian Institute of Technology (IIT) Madras.

Professor Nilesh Vasa, a faculty member at IIT Madras, explained that the development of Laser Induced Breakdown Spectroscopy began in 2009. The challenge was to adapt the technology to function under conditions similar to those on the Moon's surface, he said.

The spectrometer, a device for detecting electromagnetic radiation, had to be reduced in size to be used by the rover.

The Laser Induced Breakdown Spectroscopy works by directing a laser beam at a target, creating a plasma.

As the plasma cools down, the excited electrons settle, and the spectrometer reads the specific wavelengths associated with different elements, confirming their presence.

"Basically, we used a nanosecond pulsed laser to irradiate a material. When a laser irradiates the surface at high intensity, we end up with a plasma formation on the surface," professor Vasa said.

"When this plasma cools down, they start showing characteristic optical emissions which we capture using a spectrometer and then the spectra will consist of various atomic lines representing various elements", Vasa explained.

The analysis performed by the Pragyan rover provides valuable information about the lunar surface. The identification of elements can indicate the type of rocks and soil present, as well as the characteristics of the region.

"It may be Silicon, Iron or Hydrogen. We know that the presence of such elements will indicate the disposition of the rocks and soil. From a scientific point of view, it will be very important that we understand the surface which could be used for further scientific experiments and to know about the evolution of the surface and maybe for future use of vegetation to sustain life," said Professor Vasa.

He further added that while the Moon has almost no atmosphere and a high vacuum, trace amounts of hydrogen might be present.

If rocks or ice containing hydrogen and oxygen are found, it could indicate the presence of water molecules, which Pragyan might be able to detect with the help of LIBS.