The techie wrote to Nasa, which found there were changes on the lunar surface prior to and post Vikram’s landing
The findings confirm that though Vikram was close to the planned landing site, it crash-landed
New Delhi: The National Aeronautics and Space Administration (Nasa) has found the impact site of Chandrayaan-2’s lander, Vikram, and likely remnants scattered on the lunar surface, bringing closure to the mystery of the spacecraft missing for over two months.
The US space agency credited Chennai-based mechanical engineer Shanmuga Subramanian with the tip, and shared images of the impact crater on the Moon captured by its Lunar Reconnaissance Orbiter (LRO).
The prized lander was part of India’s second mission to the Moon—Chandrayaan-2 was launched on 22 July from Satish Dhawan Space Centre in Sriharikota. However, it went incommunicado two minutes before it was expected to make a soft landing on 7 September. At the time, the lander was believed to have made a hard landing on the Moon. The mission consisted of an orbiter, lander Vikram and rover Pragyan.
The LRO images shared by Nasa on 27 September were downloaded by people across the world. Subramanian, too, had been randomly scanning the mosaic images to find some sign of the lander. The impact point was poorly illuminated and not clearly identifiable, but Subramanian persisted and found a small bright dot about 750m from the main crash site, when he compared the images taken by LRO in September with those taken before the touchdown.
Since the mosaic was 1.3m per pixel, any spacecraft could have appeared only as a dot, which led him to surmise that the lander might have been buried in the lunar regolith (sand), as it hit the surface at high speed.
While there were doubts that the impact point of the lander could have been created by a meteorite, Subramanian said the spot appeared different from those normally seen on the Moon.
Within days, he wrote to Nasa sharing details of his discovery, after which the team scoured the surrounding area in the subsequent images taken by LRO on 14-15 October and 11 November, and found that there were indeed subtle changes on the surface before and after the impact. It then identified the impact site and debris field.
Three of the largest pieces of debris are about 2x2 pixels and cast minuscule shadows. In the images, green dots indicate the possible debris of Vikram and blue dots show the disturbed soil, where small bits of the spacecraft likely churned up the regolith. “S" indicates debris identified by Subramanian.
The findings confirm that though Vikram was close to the planned landing site near the Moon’s south pole, it crash-landed, sending debris scattering across the surface.
Nasa also contacted the Indian Space Research Organisation and shared the findings before making the announcement. The Indian space agency, too, in its latest report said the lander might have made a hard landing on the moon around 500m from the intended landing site. The landing site was about 600km from the Moon’s south pole.
Early on Tuesday, the LRO team announced the sighting on its website, crediting Subramanian with the information. Subramanian tweeted an email sent to him by Nasa congratulating him for his efforts in locating the lander.
The engineer is engaged in developing cloud native applications and providing software quality assurances. As on Tuesday, his Twitter bio reads, “I found Lander Vikram."
Despite the loss, Nasa said India getting that close to the Moon’s surface was an amazing achievement. If successful, India would have become the fourth nation to make a soft landing on the Moon after the US, Russia and China.