Chandrayaan-3 data suggests Moon was once covered in a ‘magma ocean’

New Delhi: Data from ISRO’s Chandrayaan-3 mission has bolstered the theory that the Moon was once covered in a “magma ocean,” according to a recent analysis published in the journal ‘Nature’.

The study is based on measurements of the lunar soil taken by the Pragyan rover, which traversed a 100-metre path on the Moon’s surface. The rover, deployed by the Vikram lander, which successfully touched down near the lunar south pole on August 23, 2023, provided critical data for the analysis. Chandrayaan-3, comprising the Vikram lander and Pragyan rover, was launched by the Indian Space Research Organisation (ISRO) from Bengaluru.

Researchers, including those from the Physical Research Laboratory in Ahmedabad, noted that earlier lunar missions, such as NASA’s Apollo and the Soviet Union’s Luna, primarily collected soil samples from the Moon’s equatorial and mid-latitude regions. The new data from Pragyan, gathered near the south pole, revealed that the lunar soil is predominantly composed of ferroan anorthosite (FAN), a single rock type.

The researchers found that the composition of the samples from the south pole is consistent with findings from previous missions in different regions of the Moon. This consistency across geographically distant locations supports the lunar magma ocean hypothesis, a well-regarded theory about the Moon’s early evolution.

According to this hypothesis, the Moon was formed from the debris of a colossal collision between two protoplanets, one of which became Earth and the other, the Moon. The impact left the Moon intensely hot, causing its entire mantle to melt into a “magma ocean.” As the Moon cooled, the lighter FAN floated to the surface, forming the crust, while denser minerals sank to create the mantle beneath the crust. This process explains why the Moon’s crust is largely composed of FAN.

However, the Pragyan rover also detected the presence of magnesium in the lunar soil, a finding that challenges the lunar magma ocean hypothesis.

The researchers acknowledged that some recent re-analyses of samples from the Apollo missions have also questioned this hypothesis.

Despite these challenges, the study’s authors maintained that the uniform composition of the soil, observed across regional scales and in its geological context, continues to support the lunar magma ocean theory.

The data was collected using the Alpha Particle X-ray Spectrometer (APXS) aboard the Pragyan rover, which analysed the elements present in the soil near the Chandrayaan-3 landing site, named “Shiv Shakti Point” on August 26, 2023. with agency inputs