India’s first solar mission Aditya-L1 generates Doppler velocity images of the solar corona

The generation of Doppler velocity images marks a significant achievement for ISRO and Indian space science. The VELC payload on Aditya-L1, positioned at the Lagrange Point 1 (L1), uses spectroscopic observations to study the solar corona. The principle applied is the Doppler Effect—similar to how the pitch of a siren changes as an ambulance approaches or recedes, the frequency of light from solar plasma shifts depending on its motion. A shift towards shorter wavelengths (blueshift) indicates plasma moving towards the observer (negative Doppler velocity), while a shift towards longer wavelengths (redshift) indicates plasma moving away (positive Doppler velocity). This unique capability provides unprecedented data on the dynamics of the solar corona and the early stages of Coronal Mass Ejections (CMEs).

Understanding solar activity is vital for comprehending Space Weather, which directly impacts near-Earth space and human infrastructure. Coronal Mass Ejections (CMEs) are massive clouds of hot plasma and magnetic fields expelled from the Sun. When directed towards Earth, they can interact with the Earth's magnetosphere, causing geomagnetic storms. These storms can disrupt satellite operations, GPS navigation, high-frequency radio communications, and even induce currents in power grids on the ground, potentially causing widespread blackouts. By determining the propagation direction of CMEs using VELC's Doppler imagery, scientists can provide earlier and more accurate warnings of potential space weather events, allowing for protective measures to be taken for critical infrastructure.

The success of the VELC instrument highlights India's growing self-reliance and advanced capabilities in space technology, strengthening its position in the global space economy. The data generated is crucial for protecting the vast network of communication, navigation, and earth observation satellites in orbit, which are the backbone of the modern digital economy. A severe space weather event could result in billions of dollars in economic damages due to satellite failures and power grid disruptions. By contributing to global space weather forecasting capabilities, India not only protects its own assets but also provides valuable public goods to the international community. For UPSC, understanding the economic implications of space weather and the strategic importance of missions like Aditya-L1 for safeguarding technological infrastructure is critical.