How Chandrayaan 3 rover has contributed to learning our Moon’s origin

Top left: The Chandrayaan 3 rover rolling out of the lander’s ramp during pre-launch testing; Bottom left: The co-added spectrum from all 23 lunar surface observations measured by the rover’s APXS instrument; Right: An artist’s concept of our Moon shortly after its formation, with a magma ocean and a newly forming rocky crust. Images: ISRO / Santosh Vadawale, et al. / NASA Goddard

The first ever ground-based measurements of high-latitude lunar soil and rocks made by the Chandrayaan 3 rover’s Alpha Particle X-ray Spectrometer (APXS) instrument have reinforced the scientific hypothesis that our Moon formed fully molten about 4.5 billion years ago. This key mission finding published in Nature by a group of ISRO-affiliated scientists is based on the detected elements and their abundances, from which mineral composition of the Moon’s crust can be inferred, and it’s largely similar to the crustal measurements made in the Moon’s equatorial and mid-latitude regions by past landers.

Interestingly, the Chandrayaan 3 rover Pragyan (‘wisdom’ in English) also detected slightly higher quantities of heavier minerals than elsewhere on the Moon, which scientists think must’ve been excavated to the surface from deep within the crust and/or the mantle by a gigantic past impact (geologically) shortly after our Moon’s formation, thereby lending credence to our current understanding of how Luna evolved as well.

Top left: A simplified illustration of how the Moon’s crust formed with lighter minerals floating and solidifying up top as the global magma ocean cooled; Top right: An illustration showing an asteroid impact excavating deeper crustal and mantle material onto the surface, which later on gets mixed with the uppermost crust by subsequent smaller impacts; Bottom: Measured elemental and inferred mineral compositions of the lunar surface at the Chandrayaan 3 landing site. The lighter mineral Plagioclase dominates the crust but the heavier Pyroxene and Olivine are present too. Images: LPI / PRL

The varied importance of these findings