Overview

• The CHACE-2 instrument aboard the Chandrayaan-2 orbiter detected a sharp rise in dayside exospheric pressure during a Coronal Mass Ejection.
• Derived neutral number density increased by more than an order of magnitude compared with typical background levels.
• ISRO links the transient enhancement to CME-driven surface sputtering that knocked atoms from the lunar surface into the exosphere.
• The analysis, published August 16, 2025 in Geophysical Research Letters, marks the first direct confirmation of long-standing predictions.
• ISRO says future lunar habitats and operations should factor in such space‑weather spikes when planning systems and schedules.