GS3
Science & Technology
10 marks
How did Chandrayaan-2’s CHACE-2 payload contribute to understanding the Moon’s exosphere and space weather interactions?
The lunar exosphere is an extremely tenuous, surface-bounded “atmosphere” where neutral atoms/molecules exist at very low densities. CHACE-2 (Chandra's Atmospheric Composition Explorer-2) is a mass-spectrometer-type payload onboard the Chandrayaan-2 orbiter designed to measure the composition, number density and temporal variations of these neutral species. On 10 May 2024, a series of Coronal Mass Ejections (CMEs) from the Sun impacted the Moon. CHACE-2 recorded a pronounced response: the dayside lunar exospheric total pressure rose and the total number density of neutral atoms increased by more than an order of magnitude. The data indicate an enhanced release of surface atoms into the exosphere concurrent with the CME impact.
Unique Observation:
Mechanism Behind the Observation:
Contribution to Scientific Understanding:
Practical Implications for Lunar Exploration:
Through CHACE-2, Chandrayaan-2 has provided the first concrete evidence of how solar activity influences the Moon's exosphere. This discovery bridges the gap between space weather physics and lunar science, while also guiding the design of sustainable human presence on the Moon. It showcases ISRO's growing capability in not just exploration but in fundamental planetary research as well.
GS1
Modern History
12 Dec, 2025
India is experiencing a paradox of rising food expenditure alongside declining nutritional quality. Discuss the key factors behind this trend and suggest policy measures to address the emerging nutrition crisis.
GS2
Governance
Yesterday
"Vande Mataram" has been a symbol of India’s freedom struggle and was adopted as the National Song in 1950 with only two stanzas. Discuss the historical significance of "Vande Mataram" in India’s nationalist movement and the rationale behind adopting only two stanzas officially. In your answer, also examine the relevance of the song in contemporary India.
GS2
Governance
10 Dec, 2025
“Beijing’s success in reducing air pollution offers important lessons for India’s fight against urban smog.” Discuss the key elements of Beijing’s approach and examine how these can be adapted to improve air quality in the National Capital Region (NCR).
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