Source: IE
Context:
The Indian Space Research Organisation (ISRO) announced that the CHACE-2 payload onboard the Chandrayaan-2 lunar orbiter has made the first-ever direct observation of the Sun’s Coronal Mass Ejection (CME) impacting the Moon.
About CHACE-2 (Chandra’s Atmospheric Composition Explorer-2):
- Type: Neutral gas mass spectrometer
- Mission: Part of Chandrayaan-2 orbiter
- Launch Date: 22 July 2019, aboard GSLV Mk-III M1
- Purpose: Study the Moon’s lunar exosphere (extremely thin atmosphere)
Objectives:
- Analyze chemical composition, spatial and temporal variations, and density of the lunar exosphere (mass range: 1–300 amu)
- Detect water vapour and heavier molecules
- Understand lunar surface–exosphere interactions
Key Features:
- Successor to CHACE (Chandrayaan-1) and MENCA (Mars Orbiter Mission) instruments
- Measures neutral gases and isotopic abundances in situ
- Detects noble gases such as Argon-40 and their distribution
- Provides real-time data on exosphere composition and dynamics
- Assists in modeling lunar surface processes and space weather effects
Recent Discoveries:
- On 10 May 2024, CHACE-2 recorded the first evidence of a CME-induced increase in lunar exosphere pressure
- Observed a tenfold rise in total number density of neutral atoms, validating theoretical predictions
- Provided critical insights into how solar activity alters lunar atmospheric conditions
- Implications for future lunar bases and space weather prediction





