IIT Bombay students mapped Moon's surface chemistry using data from Chandrayaan-2. They used data from CLASS (Chandrayaan-2 Large Area Soft X-ray Spectrometer), an instrument that detects X-ray fluorescence from Moon's surface. CLASS scanned the Moon from 100 km altitude, collecting data each orbit. Analysing these signals helped the students study Moon's chemical composition, IIT Bombay said.