Chandrayaan 2: Despite a frantic search for the Vikram Moon lander by scientists at ISRO and US space agency NASA for over two months since it disappeared on Moon's surface on September 7, it's a techie from Chennai who was finally able to unravel the biggest mystery in India's space history so far. The United State's premier space agency, NASA, has credited Shanmuga Subramanian (Shan), a mechanical engineer and a computer programmer from Chennai, for helping it find ISRO's Vikram Moon lander debris on the lunar surface.
Shanmuga works as a technical architect at engineering company Lennox India Technology Centre in Chennai.
As per NASA, its Lunar Reconnaissance Orbiter Camera (LROC) had released the first set of pictures of the Vikram lander contact site on September 26. It said many people, including Shanmuga Subramanian, were searching for the lander, which lost contact with the ISRO just before soft-landing on the Moon. Shanmuga's crucial inputs helped NASA confirm the Vikram lander debris location by comparing before and after images.
"Shanmuga Subramanian contacted the LRO project with positive identification of debris. After receiving this tip, the LROC team confirmed the identification by comparing before and after images," the agency said, crediting Shanmuga for finding debris identified as "S" (check the main image).
@NASA@LRO_NASA@isro— Shan (@Ramanean) November 17, 2019
This might be Vikram lander's crash site (Lat:-70.8552 Lon:21.71233 ) & the ejecta that was thrown out of it might have landed over here https://t.co/8uKZv7oXQa (The one on the left side was taken on July 16th & one on the right side was from Sept 17) pic.twitter.com/WNKOUy2mg1
In an email to The New York Times, Shan said he was among several curious Indians who were searching for the Vikram lander. "The crash landing of Vikram rekindled an interest in the moon not only for me and others also," he wrote, adding that, "I think even if Vikram had landed and sent some images, but we also would have never had such interest. For the first few days, I was scanning the images randomly and there were a lot of false positives."
During his random searches at his spare time, Shanmuga noticed a white speck around the Moon touchdown site pictures released by NASA. This bright pixel, he said, was not visible in earlier images released by the space agency. "Is this Vikram lander? (1 km from the landing spot) Lander might have been buried in Lunar sand?" he wrote in an October 3 tweet, tagging both ISRO and NASA.
Thanking Subramanian for an interesting observation, Nasa's deputy project scientist (LRO mission) John Keller said its LROC team confirmed that location did exhibit changes in images taken before and after the day of landing. "Using this information the LROC team did additional searches in this area and located the site of the primary impact as well as other debris around the impact location," Keller wrote to Subramanian.
He also appreciated Shanmuga for his efforts. "Congratulations for what I am sure was a lot of time and effort on your part. You will probably get some enquiries from the press on your discovery."
Releasing pictures of the contact site, NASA said the debris first located by Shanmuga is about 750 metres northwest of the main crash site. " (It) was a single bright pixel identification in that first mosaic (1.3-metre pixels, 84-degree incidence angle). The November mosaic shows best the impact crater, ray and extensive debris field. The three largest pieces of debris are each about 2x2 pixels and cast a one-pixel shadow," the agency said.
The Chandrayaan 2's Vikram lander was targeted to land on Moon's highland smooth plain, about 600 kilometres from its the South Pole. However, India's attempt to create history by becoming the first nation to land on the South Pole had faced setback after Vikram lander lost communication just before the scheduled touchdown on September 7.
NASA had earlier made two attempts to locate Chandrayaan 2's lander on September 17 and October 14 but to no avail. The agency had cited two reasons for its inability to trace Chandrayaan 2's Vikram lander -- one, the lander might be lying in shadowed part of the moon or second, it might be located outside the area US space agency photographed.
Edited by Manoj Sharma