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lmost two and a half years since the landing of Chandrayaan-3 on the Moon's south pole, there is one more surprising discovery that has been made through the data collected.
As per a recent study conducted using the Pragyan rover data collected from the spacecraft mission, it has been revealed that the composition of soil on the Moon where the spacecraft landed and named the Shiv Shakti Station is similar to that of ALHA 81005, which was the first meteorite discovered to be from the Moon.
The Chandrayaan-3 landed on August 23, 2023, on the surface of the Moon, in the south high latitudes, which is an understudied region compared to the equatorial regions, where the Apollo and Luna rovers have already operated. The rover possessed an instrument called an Alpha Particle X-ray Spectrometer (APXS), which used alpha particles and X-rays for analysis of the composition of lunar soil and reflection analysis.
The results of the analysis from the Shiv Shakti Station using APXS have been compared with 66 lunar meteorites that have been found on Earth over many years. The meteorites were primarily collected in Antarctic and North African deserts since the impact made them leave the surface of the Moon and land on Earth. The most similar sample was ALHA 81005.
They had almost the same levels of aluminum oxide and very similar amounts of the combination of iron oxide and magnesium oxide. They are also uniquely placed in terms of composition between two major types of lunar rock: ferroan anorthosites, which are light, aluminum-rich rocks that are found on the lunar highlands, and Mg-suite rocks, which are magnesium-rich rocks and thought to be formed deep within the crust.
Scientists did not leave any stone unturned in making sure that they drew clear boundaries when making the discovery. It does not mean at all that ALHA 81005 was derived from the Shiv Shakti Station. This means only that ALHA 81005 and the Shiv Shakti Station are of the same kind of magnesium-rich rocks that form the crust of the moon and its regolith, which is the thin layer of dust and broken rocks covering the moon's surface.
It was also found out from the analysis that the soil in the landing site area is not homogenous in its composition either.
The soil is believed to contain not one type of mineral but the mixtures of minerals derived from several layers of the Moon's crust, including the fragments of magnesium-based rocks, which must have formed deeper inside the lunar crust and been exposed to the surface through previous impacts.
As stated by ISRO, this indicates that the Moon's crust in this southern area must be more chemically heterogeneous than previously thought from the missions near the lunar equator.
Most of the samples collected on the Moon's surface came from near the lunar equator due to the fact that all Apollo and Soviet Luna missions landed in this area, leaving most high-latitude areas almost unexplored until now. Every single data returned by Pragyan's instruments is especially valuable in this case because it allows us to learn about the evolution of the Moon's crust in a new territory, which is now seen as a promising target for future missions due to the water presence in shadow craters.
In linking a specific meteorite to soil samples collected from a specific location on Earth, this research offers scientists an invaluable point of reference. Meteorites are valuable as researchers are able to analyze them down to microscopic detail in laboratories here on Earth; however, prior to this research, no one could claim with certainty what specific region of the Moon a specific lunar meteorite came from. Research such as this helps bridge the gap between lunar meteorites and their origin, even if in a broad geographical context.
The Indian Space Research Organization (ISRO) stated that this discovery provides new pathways toward studying the formation of the early crust on the Moon, a process that occurred about 4 billion years ago.
