Overview
- CHACE-2 on the Chandrayaan-2 orbiter measured a sharp rise in total pressure on the Moon’s sunlit exosphere during a CME on May 10, 2024.
- The neutral number density increased by more than an order of magnitude during the event, aligning with earlier theoretical models.
- ISRO says this marks the first direct measurement by any lunar mission of a CME altering the Moon’s exosphere.
- The study was published in Geophysical Research Letters on August 16, 2025, with ISRO’s M.B. Dhanya as lead author.
- ISRO notes the result has engineering implications for surface operations and habitat design, as the still-operational orbiter continues science from a 100 km lunar orbit.