Moon Was Once A Fiery Ball Of Molten Rock: ISRO Confirms In New Study

The Moon we see today was once a hot and fiery ball of molten rock a big finding being confirmed by the science team of ISRO's Chandrayaan-3.

The team has published the first scientific results from the instruments that flew to the Moon onboard the Pragyan Rover. The landmark paper has been published today in the prestigious British scientific journal. Nature, which publishes only significant scientific breakthroughs.

The lead author of the paper, Dr Santosh V. Vadawale, a scientist at the Physical Research Laboratory (PRL), Ahmedabad who led the team of nearly three dozen scientists said "By analysing the lunar soil, our team confirms that the Moon was once a molten ball of rock some 4.4 billion years ago, soon after its birth."

It is called the Lunar Magma Ocean (LMO) hypothesis. Experts have theorised that a Mars-size planetary body struck Earth some 4.5 billion years ago which led to the ejection of mass high into space which then coalesced to form the Moon. Mr Vadawale said, "The primordial Moon was all molten magma like one sees in the core of the Earth with a temperature of about 1500 degrees Celsius."  

When India landed at the Shiv-Shakti point near the South Pole, it created global history since no other nation had landed in that region and it was then known that whatever Indian scientists find will be a novelty. Interestingly the elemental composition of the lunar soil is not drastically different from the soil one sees on Earth, Mr Vadawale said. Since there is no weathering on the moon the finding also provides a peek into the deep historical past of the Solar System.

Speaking to NDTV, Dr S Somanath Chairman of ISRO said "Chandrayaan-3 not only proved India's technological and engineering prowess by soft landing but now this milestone scientific paper in the prestigious journal Nature shows India also did breakthrough scientific analysis by providing the first in-situ elemental composition analysis of lunar soil nearer the South Pole at Shiv-Shakti Point. India is the first country to have ever done this. An exciting finding that opens up possibilities of creating permanent habitation on the moon in the future."

The six-wheeled 26-kilogram Pragyan moon rover travelled nearly 103 metres on the lunar surface in the course of its 10-day life. It travelled at a princely speed of one centimetre per second.

In a statement, the Nature journal said "An analysis of lunar soil in the Moon's southern high-latitude regions, performed using data from India's Chandrayaan-3 mission, suggests the presence of remnants of a former ocean of magma".

Adding that previous research into the Moon's geology has primarily relied on samples taken by missions to lunar mid-latitudes, such as the Apollo programme. However, in August 2023, India's Vikram lander - part of the Chandrayaan-3 mission - successfully made a soft landing near the south pole of the Moon. The Pragyan rover then took 23 measurements at various spots along a 103-metre tract of the lunar surface using its onboard alpha particle X-ray spectrometer, which measured the elemental composition of the Moon's regolith or the moon soil.

Santosh Vadawale and colleagues analysed Pragyan's measurements and found a relatively uniform elemental composition in the lunar regolith surrounding the lander, which primarily contained the rock-type ferroan anorthosite. They note that the composition measurements of the lunar South Pole are intermediate between those of the samples from the Moon's equatorial region taken by the Apollo 16 and Luna-20 missions. The authors suggest that the similar chemical composition of these geographically distant samples supports the Lunar Magma Ocean hypothesis.

In this hypothesis, as the Moon cooled during its formation, less dense ferroan anorthosite floated to the lunar surface while heavier minerals sank to form the mantle. Dr Vadawale and colleagues suggest that the magnesium minerals that were also detected by Pragyan, which cannot be explained by the Lunar Magma Ocean hypothesis, are likely deeper material excavated by the nearby South Pole-Aitken impact.

The authors conclude that the composition of Vikram's landing site is consistent with the LMO hypothesis, which predicts that the lunar highlands were formed as a result of the floatation of lighter anorthositic rocks.

Since the Moon's soil is not very different in elemental composition from the soil we see on Earth, the landmark finding by Chandrayaan-3 opens the tantalizing opportunity to use the same lunar regolith to do agriculture on the Moon as when it is permanently inhabited. It would be controlled growth of vegetation in chambers and water and organic matter will of course have to be added.