Chandrayaan-2 Lunar Orbiter Makes Historic Observation on Solar Eruption's Impact on Moon's Atmosphere

The Chandrayaan-2 lunar orbiter has made a groundbreaking observation of how a massive solar eruption affects the moon's tenuous atmosphere. The discovery, made by the CHACE-2 instrument onboard, provides direct evidence of how sun's coronal mass ejections (CMEs) interact with airless celestial bodies like the moon. The observation was made when a CME struck the moon on May 10, causing a sharp rise in total pressure and number density in the lunar dayside exosphere. This finding confirms theoretical models that predicted solar events could alter the lunar exosphere temporarily.

Key Takeaways:

• The Chandrayaan-2 lunar orbiter's CHACE-2 instrument detected a sharp rise in total pressure and number density in the lunar dayside exosphere after a CME struck the moon on May 10.
• The observation provides direct evidence of how CMEs interact with airless celestial bodies like the moon.
• The study confirms longstanding theoretical models that predicted solar events could momentarily alter the lunar exosphere.
• The moon's exosphere is primarily shaped by solar radiation, the solar wind, and micrometeorite impacts.
• Unlike Earth, the moon lacks a global magnetic field or a substantial atmosphere to shield it from solar activity.
• The study's findings are crucial for scientific interpretation and engineering design for future lunar missions, including India's long-term stay and research stations on the moon.
• Engineers and scientists designing lunar habitats and instruments will need to account for temporary but significant environmental changes triggered by CMEs.

Statistics:

• The sharp rise in total pressure in the lunar dayside exosphere was detected by CHACE-2 after the CME struck the moon.
• The number density in the lunar dayside exosphere increased significantly after the CME impact.
• The temporal changes in the lunar exosphere lasted for a considerable duration after the solar event.
• The study provides valuable data for mission planning for future lunar missions, including India's long-term stay and research stations on the moon.
• The moon's exosphere is predominantly composed of atoms and molecules influenced by solar radiation, the solar wind, and micrometeorite impacts.

Sources:

• "Impact of a Coronal Mass Ejection on the Lunar Exosphere as Observed by CHACE-2 on the Chandrayaan-2 Orbiter", published in Geophysical Research Letters.
• Isro [Note: No specific date or time provided in the original text]