NEW DELHI: The dual-frequency synthetic aperture radar on board Chandrayaan-2’s orbiter, circling at 100km altitude over Moon’s surface, has taken colourful images of impact craters that will cast light on the age and origin of the craters in the lunar south pole region, which, in turn, will help understand the evolution of Moon. In another Chandrayaan-2-related development, US space agency Nasa has clarified that it has found no evidence of Vikram lander in the latest lunar images of the south pole region taken by its orbiter Lunar Reconnaissance Orbiter (LRO) during a recent flyby. The L & S bands of the synethic aperture radar (SAR), a powerful remote sensing instrument for studying planetary surfaces and subsurface, are giving details about the morphology of impact craters due to its ability of imaging with higher resolution and wide range of incidence angle coverage, a statement from Indian Space Research Organisation said. The colourful images of the lunar surface taken by the synthetic aperture radar of Chandrayaan-2 orbiter, capturing impact craters. One of the two images presents many interesting facts about the secondary craters of different ages and origins in the lunar south polar region. The yellowish tone around crater rims in the image shows ejecta fields.The impact craters are circular depressions on the lunar surface caused due to continuous bombardment of meteorites, asteroids and comets. The bombardment has resulted in the formation of innumerable impact craters that form the most distinct geographic features on the lunar surface. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters typically have raised rims and floors that are lower in elevation than the surrounding terrain. The study of the nature, size, distribution and composition of impact craters reveal valuable information about the origin and evolution of craters. In addition to giving details about the morphology of the impact craters, the greater depth penetration power of L-band (3-5 metre) is helping scan the buried terrain of Moon to a greater depth. The L & S bands are also helping in identify and quantitatively estimate the lunar polar water ice lying in permanently shadowed regions. The previous lunar-orbiting SAR with single S-band on Chandrayaan-1 orbiter and SAR on Nasa’s LRO had provided valuable data on scattering characterisation of ejecta materials (material that came out of volcanic explosions) of impact craters. Meanwhile, Nasa project scientist Noah Edward Petro said the LRO images of the south pole area of the targeted Chandrayaan-2 Vikram landing site on October 14 did not observe any evidence of the lander, an agency report said. Petro said the LRO camera team carefully examined the lunar images and employed the change detection technique but could not locate the lander, which had made a “hardlanding” on Moon on September 7.
Chandrayaan-2: Orbiter’s radar takes colourful lunar images of impact craters, will cast light on Moon’s – Times of India
