Chandrayaan-3 landed in one of Moon’s oldest craters, Isro scientists claim discovery

Chandrayaan-3 landed in one of Moon’s oldest craters, Isro scientists claim discovery

BENGALURU: Scientists from the Physical Research Laboratory (PRL) and others from ISRO have shown that India’s Chandrayaan-3 landed within a buried impact crater, which is around 160 km in size, around 4.4 km deep, and likely to be older than the South Pole Atkin (SPA) basin.
“This buried crater is one of the oldest craters on the Moon, and the Chandrayaan-3 lander (Vikram) and rover (Pragyan) landed and roved within this buried crater, which is hosting the SPA basin ejecta material and some of the most deeply excavated materials on the Moon,” ISRO said Tuesday.
Ejecta means material that is forced or thrown out, especially as a result of volcanic eruption, meteoritic impact, or stellar explosion.
Their findings are based on analysis of images obtained by navigation cameras (navcams) on Chandrayaan-3 rover (Pragyan) and Chandrayaan-2 orbiter’s Optical High Resolution Camera (OHRC). The work, authored by S Vijayan, KB Kimi, Anil Chavan, R Aditi, U Thahira, V Rama Subramanian, Rishitosh K Sinha, Santosh Vadawale, M Shanmugam, NPS Mithun, Arpit R Patel, S Amit Basu, KV Iyer, K Suresh, Ajay Prashar, G Rima and Anil Bhardwaj, has been published as a study in the peer-reviewed journal Icarus.
“The Chandrayaan-3 mission with the lander (Vikram) and Pragyan landed in the high latitude highland region near the south pole of Moon. The landing site is located around 350 km from the South Pole-Aitken basin rim, an ancient and the largest impact basin in the Solar System,” ISRO said Tuesday.
It added that this landing site has undergone the complex emplacement sequence of SPA basin ejecta followed by the nearby and distant impact basins and complex crater ejecta materials.
“We found that the SPA basin is the major contributor, which deposited nearly around 1400 m of ejecta materials, and 11 other basins deposited around 580 m of ejecta. The other complex craters contributed up to around 90 m of ejecta. Meanwhile, secondary craters of a few kilometres in diameter located adjacent to the Vikram lander contributed to around 0.5 m ejecta, which are crucial target materials for the Pragyan’s in-situ analysis,” ISRO said.
Images from Pragyan’s navcams and the OHRC gave the first clue about the linear, distal ejecta rays or groove-like structures possibly formed due to the distant impacts deposited at the Chandrayaan-3 landing site, the scientists said.

“The regional exploration around the Chandrayaan-3 landing site revealed a near semi-circular like structure, highly degraded in nature. This structure encompassed the Statio Shiv Shakti (yellow star). Further detailed geomorphological and topographical analysis revealed that the structure is a heavily degraded crater structure or a buried impact crater with a diameter of around 160 km,” ISRO said.