Chandrayaan-3’s lander module, Vikram, had generated an ‘ejecta halo’ on the lunar surface while making the historic touchdown on the south pole of the moon on August 23.
According to a new study, Vikram raised lunar dust and generated a bright patch around itself when it landed on the moon.
”Chandrayaan-3 Results: On August 23, 2023, as it descended, the Chandrayaan-3 Lander Module generated a spectacular ‘ejecta halo’ of lunar material. Scientists from NRSC/ISRO estimate that about 2.06 tonnes of lunar epi regolith were ejected and displaced over an area of 108.4 m² around the landing site”, ISRO posted on X (formerly Twitter).
These findings were published in an article titled Characterisation of Ejecta Halo on the Lunar Surface Around Chandrayaan-3 Vikram Lander Using OHRC Imagery, in the Journal of the Indian Society of Remote Sensing on October 26.
“The Vikram lander of the Chandrayaan-3 mission landed near the south pole of the moon on August 23. During the action of descent stage thrusters and the consequent landing, a significant amount of lunar surficial epi regolith material got ejected, resulting in a reflectance anomaly or ejecta halo”, states the abstract of the article, authored by Swati Singh, Prakash Chauhan, Priyom Roy, Tapas R. Martha and Iswar C. Das from ISRO’s National Remote Sensing Centre (NRSC), Hyderabad.
The authors added that they compared the pre- and post-landing high-resolution panchromatic imagery from Orbiter High-Resolution Camera (OHRC) of the Chandrayaan-2 orbiter, acquired hours before, and after the landing event, and characterised this ejecta halo as an irregular bright patch surrounding the lander.
“From the mapped and classified, uncorrelated ejecta halo pixels, an approximate areal extent of 108.4 m2 is estimated to have been covered by lunar epi regolith ejecta displaced due to the landing sequence of the Vikram lander. Further, using empirical relations, we estimate that approximately 2.06 tonnes of lunar epi regolith were ejected due to the landing event,” the authors added.
India became the fourth country to successfully land a spacecraft on the moon, and the first nation to touch down in the polar region when the Chandrayaan-3’s lander module, with the rover in its belly, successfully made a soft landing on the lunar surface on August 23.
Since landing on the moon, Vikram and Pragyan Rover have carried out many in-situ measurements, like confirmation of the presence of sulphur in the region, and detecting the presence of minor elements, among other things.
Vikram also achieved a significant milestone, as it successfully undertook a hop experiment when the lander — on command — fired the engines, elevated itself by about 40 cm, and landed safely at a distance of 30-40 cm away.
The lander and the rover went to sleep after the end of one lunar day (14 Earth days). Efforts to wake them up have not been successful so far.
