Chandrayaan-2 Unveils Lunar Secrets: Witnessing the Moon's Direct Reaction to a Solar Storm

In a groundbreaking first for an Indian mission, ISRO's Chandrayaan-2 orbiter has directly observed the Moon's dramatic response to a powerful solar coronal mass ejection (CME). This remarkable detection, made possible by the Chandra X-ray Spectrometer (CLASS) instrument, offers unprecedented insights into lunar space weather and the Moon's intricate dance with the Sun's most energetic outbursts.

The event in question originated from a significant solar flare in December 2021, which hurled a massive cloud of plasma and magnetic field, known as a Coronal Mass Ejection, towards our celestial neighbour.

By January 2022, this solar storm had reached the Moon. Chandrayaan-2, meticulously orbiting above the lunar surface, was perfectly positioned to capture the ensuing spectacle.

What CLASS detected was the distinct signature of solar energetic particles (SEPs) impacting the lunar surface. These high-energy particles, accelerated during the CME, caused the Moon's surface elements to fluoresce, emitting X-rays that were then measured by Chandrayaan-2.

This phenomenon, known as X-ray fluorescence (XRF), provides a direct fingerprint of the Moon's composition and its instantaneous reaction to the solar onslaught.

This observation is not merely a scientific curiosity; it holds profound implications for future lunar exploration. Understanding the precise nature of lunar space weather, particularly the impact of CMEs and SEPs, is crucial for assessing the radiation environment.

This data is vital for designing safe habitats and protective measures for astronauts and equipment during long-duration missions to the Moon, as the Moon lacks a substantial atmosphere and magnetic field to shield it from such cosmic assaults.

Until now, our understanding of how the Moon interacts with CMEs largely relied on theoretical models and indirect observations.

Chandrayaan-2's direct detection provides empirical evidence, validating these models and offering a more precise picture of the complex processes at play. This capability of CLASS, designed to map the Moon's elemental composition using X-ray fluorescence, has proven invaluable in its extended mission, showcasing its versatility in monitoring dynamic space weather events.

The data from Chandrayaan-2's CLASS instrument significantly contributes to a broader understanding of planetary space weather.

It helps scientists comprehend how celestial bodies, particularly those without robust protective magnetospheres, respond to the Sun's volatile activity. Such knowledge is not only key to our lunar ambitions but also enhances our insights into the evolution of planetary atmospheres and surfaces throughout the solar system.

ISRO's Chandrayaan-2 continues to push the boundaries of lunar science, transforming our comprehension of the Moon from a static, unchanging body to a dynamic environment constantly influenced by the Sun.

This discovery underscores India's growing prowess in space exploration and its commitment to unraveling the universe's most intriguing mysteries.