Chandrayaan-2 Unveils Lunar Secrets: First Direct Proof of Solar Storms Hitting Moon's Atmosphere

In a groundbreaking achievement that redefines our understanding of the Moon's interaction with the Sun, India's Chandrayaan-2 orbiter has delivered the first direct evidence of solar storms impacting the lunar atmosphere. This monumental discovery, made possible by the Chandrayaan-2 Large Area Soft X-ray Spectrometer (CLASS) instrument, opens new frontiers in space weather research and holds profound implications for future human missions to the Moon.

For decades, scientists have known that the Moon, lacking a thick atmosphere, is constantly bombarded by solar winds.

However, the direct observation of X-ray signatures from powerful solar events like coronal mass ejections (CMEs) and solar flares interacting with the lunar surface and its tenuous exosphere remained elusive until now. Chandrayaan-2's CLASS instrument has precisely captured these unique X-ray emissions, providing unequivocal proof of how solar storms perturb the Moon's incredibly thin atmospheric layer.

The mechanism behind this fascinating phenomenon involves a process known as 'charge exchange.' When highly energetic particles, primarily protons and electrons, ejected during solar storms, strike the lunar surface, they interact with the atoms of the Moon's extremely thin exosphere.

During this interaction, these particles can pick up electrons from the lunar surface or the exospheric gases, becoming neutralized and then re-emitting in the X-ray spectrum. The CLASS instrument, with its acute sensitivity, was able to detect these distinct X-ray signatures, serving as a beacon of the Moon's dynamic response to solar activity.

This discovery is far more than a mere scientific curiosity; it is a critical piece of the puzzle for future lunar exploration, especially with ambitious initiatives like NASA's Artemis program aiming to establish a sustainable human presence on the Moon.

Understanding how solar storms affect the lunar environment is paramount for designing robust shielding for spacecraft, habitats, and, most importantly, for safeguarding astronauts who will live and work on the lunar surface. Solar storms can significantly increase radiation levels, posing serious health risks and potentially disrupting sensitive electronic equipment.

The data collected by Chandrayaan-2 provides invaluable insights into space weathering processes—the effects of the space environment on the surfaces of airless bodies.

It helps scientists comprehend how the lunar regolith (soil) and rocks are altered over time by cosmic rays and solar particles. This knowledge is crucial for future resource utilization on the Moon and for interpreting geological data from lunar samples.

Developed by the Physical Research Laboratory (PRL), an autonomous unit under the Department of Space, Government of India, the CLASS instrument continues to demonstrate its exceptional capabilities.

This breakthrough underscores ISRO's commitment to advancing global space science and solidifies India's position at the forefront of lunar research. The findings from Chandrayaan-2 will undoubtedly influence the strategies and technologies developed for upcoming lunar missions, ensuring safer and more effective human exploration of our celestial neighbour.

As humanity looks towards a future of permanent settlements on the Moon, understanding every aspect of its environment, including its vulnerability to powerful solar events, becomes increasingly vital.

Chandrayaan-2's latest revelation is a testament to meticulous planning and scientific ingenuity, paving the way for a deeper and safer engagement with the Moon.