Indian moon rover detects sulphur and other elements on lunar surface

30 Aug 2023

Image of the Vikram lander taken by Pragyaan. Image: ISRO

India’s moon rover has ‘unambiguously’ detected sulphur on the surface of the moon’s south pole. An investigation is underway to detect hydrogen.

An instrument aboard the Indian moon rover Pragyaan has made the first-ever in-situ detection of several elements, including sulphur, on the moon’s unexplored south pole as part of the Chandrayaan-3 lunar mission.

Known as a laser-induced breakdown spectroscopy, or LIBS, the instrument onboard Pragyaan “unambiguously” confirmed the presence of sulphur in the south pole region of the moon while taking measurements on the elemental composition of the lunar surface.

India’s space agency, the Indian Space Research Organisation (ISRO), wrote in its update this week that such measurements have not been feasible using instruments onboard other orbiters.

“LIBS is a scientific technique that analyses the composition of materials by exposing them to intense laser pulses,” ISRO explained. “A high energy laser pulse is focused onto the surface of a material such as a rock or soil. The laser pulse generates an extremely hot and localised plasma.”

Scientists can then determine the elemental composition of the material because each element emits a characteristic set of wavelengths of light when in a plasma state.

The Pragyaan rover has so far been able to detect, based on preliminary analyses, the presence of aluminium, sulphur, iron, chromium, titanium, manganese, silicon and even oxygen on the lunar surface.

ISRO said a “thorough investigation” is underway to determine whether hydrogen is also present on the moon’s south pole. Hydrogen is one of the building blocks of water – finding which is one of the main objectives of the Chandrayaan-3 mission.

Launched on 14 July, Chandrayaan-3 was India’s third attempt at landing a spacecraft on the moon. The spacecraft will study the unexplored parts of the moon in search of frozen water, among other things, that can one day prove crucial for astronauts to survive on the surface.

The Vikram lander carrying Pragyaan made a historic soft landing on the lunar south pole a week ago, making India the first country to achieve the feat and the fourth country to land on the moon.

India’s landing came just two days after Russia’s Luna-25 mission, which was attempting to land in the same region as India, crashed into the lunar surface after running into difficulties.

The previous Chandrayaan-2 mission was launched four years ago to explore water deposits that were confirmed by a previous mission, the Chandrayaan-1, which made headlines and orbited the moon before malfunctioning a year later.

Now, after the success of Chandrayaan-3, the country has its eyes on the sun. ISRO confirmed this week that its latest Aditya L1 mission to study the sun will be launched into orbit around the Lagrange point 1 on Saturday (2 September) to observe solar activities.

“A satellite placed in the halo orbit around the L1 point has the major advantage of continuously viewing the sun without any occultation or eclipses,” ISRO said. “This will provide a greater advantage of observing the solar activities and its effect on space weather in real time.”

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Vish Gain is a journalist with Silicon Republic