Chandrayaan-3 Landed on One of the Moon's Oldest Craters, Say Researchers
Scientists have revealed that India’s Chandrayaan-3 mission may have landed in one of the Moon’s oldest craters, formed during the Nectarian period approximately 3.85 billion years ago. This period is among the earliest in the Moon's geological history, according to a team that includes researchers from the Physical Research Laboratory and the indian space research organisation (ISRO) in Ahmedabad.
S. Vijayan, an associate professor in the Planetary Sciences Division at the Physical Research Laboratory, stated, “The landing site of Chandrayaan-3 presents a unique geological context where no other missions have explored. The images captured by the Pragyan rover are the first taken on-site at this latitude, shedding light on the Moon's evolutionary history.”
The researchers noted that a crater forms when an asteroid impacts a larger celestial body, displacing material known as ‘ejecta.’ The images from the mission indicated that one half of the crater is buried under ejecta from the South Pole-Aitken basin, the largest known impact basin on the Moon.
Vijayan explained, “The process of forming ejecta is akin to throwing a ball on sand, which displaces some of it outward.” He added that when an impact basin forms, surdata-face materials are thrown out, and larger basins excavate materials from greater depths.
Chandrayaan-3 landed within a crater approximately 160 km in diameter, identified in the images as a nearly semi-circular structure. The researchers noted that one half of this crater is likely degraded due to burial under ejecta from the South Pole-Aitken basin. Additionally, ejecta from another distant impact crater was detected near the landing site, confirming that similar material exists there.
The Pragyan rover was deployed on the lunar surdata-face by the vikram lander of Chandrayaan-3, which successfully made a soft landing near the Moon’s south pole on august 23, 2023. The site was named Shiv shakti Point on august 26, 2023.
To validate their findings, researchers studied other craters from the Nectarian period and found that most were significantly degraded, supporting the conclusion of a buried crater and indicating the weathering effects from exposure to space, commonly referred to as ‘space weathering.’