Chandrayaan-2's Observations on the Lunar Exosphere
Context:
The Indian Spac tge Research Organisation (ISRO) has reported that India's Chandrayaan-2 mission has made the first-ever direct observation of the effects of a sun's Coronal Mass Ejection (CME) on the moon
Key Payload and Observation
The observation was made by the Chandra's Atmospheric Composition Explorer-2 (CHACE-2) payload.
CHACE-2 is onboard the Chandrayaan-2 orbiter
On May 10, 2024, a rare series of CMEs were hurled by the sun.
When this CME impacted the moon, CHACE-2 detected significant changes
The payload observed an increase in the total pressure of the dayside lunar exosphere (the moon's very thin atmosphere).
The total number density (number of neutral atoms/molecules) in the exosphere increased by "more than an order of magnitude"
Mechanism
The enhancement of the lunar exosphere occurred because the increased quantity of solar coronal mass from the CME impacted the moon's surface.
This powerful impact "knocked off" atoms from the lunar surface, liberating them into the exosphere and thereby increasing its total pressure.
Significance of the Finding:
This is the first time such an effect has been directly observed.
Previously, it had only been predicted by theoretical models
The observation provides crucial scientific insight into the lunar exosphere and how space weather (like CMEs) affects the moon
This finding highlights the challenges for building future scientific bases on the moon. We must now account for such extreme space weather events, which can temporarily alter the lunar environment
About Chandrayaan-2
The mission was launched on July 22, 2019, using the GSLV-MkIII-M1 rocket
It carried eight experimental payloads.
While the Vikram lander's soft landing attempt failed.
The orbiter (which carries the CHACE-2 payload) remains operational and continues to provide valuable data.
