ISRO reports 'ejecta halo' formation during Chandrayaan 3 landing. Explanation?
Chandrayaan 3 Update: ISRO reports 2.06 tonnes of lunar epi-regolith ejected during landing, forming an 'ejecta halo.' Significance explained.
The Indian Space Research Organisation (ISRO) made an exciting revelation recently, sharing details about the Chandrayaan-3 mission. On August 23, 2023, the Chandrayaan-3 Lander Module created a remarkable phenomenon on the lunar surface known as an 'ejecta halo' as it descended toward the Moon's south pole.
In an update shared on X, formerly known as Twitter, ISRO disclosed that scientists from the National Remote Sensing Centre (NRSC) and ISRO have estimated that approximately 2.06 tonnes of lunar epiregolith were ejected and scattered over an area measuring 108.4 square meters around the landing site.
Chandrayaan-3 Results:— ISRO (@isro) October 27, 2023
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 epiregolith were ejected and displaced over an area of 108.4 m²…
But what exactly is this 'ejecta halo'? It's a consequence of the lander module's descent, which involved the use of descent stage thrusters and culminated in a soft landing on the lunar surface. During this process, a significant amount of lunar surficial epiregolith material, which encompasses lunar rocks, soil, and Moon dust, was ejected.
The lunar epiregolith material, weighing approximately 2.06 tonnes, was displaced over the 108.4 square meter area. This displacement resulted in the formation of the visually striking 'ejecta halo,' described as an irregular bright patch surrounding the lander.
A team of researchers, including Swati Singh, Prakash Chauhan, Priyom Roy, Tapas R. Martha, and Iswar C. Das from ISRO's National Remote Sensing Centre (NRSC) in Hyderabad, conducted an in-depth analysis of the 'ejecta halo.' Their findings were subsequently published in the "Journal of the Indian Society of Remote Sensing" under the title "Characterisation of Ejecta Halo on the Lunar Surface Around Chandrayaan-3 Vikram Lander Using OHRC Imagery."
The study involved comparing high-resolution panchromatic imagery from the Chandrayaan-2 orbiter's Orbiter High-Resolution Camera (OHRC) captured before and after the landing event. Through this comparison, they characterized the 'ejecta halo' and estimated its areal extent to be approximately 108.4 square meters. Using empirical relations, the researchers calculated that roughly 2.06 tonnes of lunar epiregolith were ejected due to the landing event.
The Chandrayaan-3 mission achieved a significant milestone with the successful soft landing of the Vikram lander on the Moon's south pole on August 23, 2023. This accomplishment not only marked India as the first country to achieve a soft landing on the Moon but also positioned it as the fourth nation, following the United States, China, and Russia, to successfully land on the lunar surface. The 'ejecta halo' discovery stands as a testament to India's remarkable progress in lunar exploration.