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Tracking Coronal Mass Ejections (CMEs) with Precision

Indian scientists have revealed key findings from Aditya-L1, India’s first solar observation mission in space. These discoveries are crucial for protecting Earth’s power grids and satellites from harmful solar activity.

On July 16, Aditya-L1’s Visible Emission Line Coronagraph (VELC) recorded data that helped identify when a coronal mass ejection (CME) began. CMEs are massive bursts of charged particles from the Sun’s corona, and tracking them is a major mission goal.

CMEs can weigh up to a trillion kilograms and travel at speeds of 3,000 km (1,864 miles) per second. When directed at Earth, they can cause serious disruptions, covering 150 million km in just 15 hours. Prof. Ramesh, a leading scientist from the Indian Institute of Astrophysics, described CMEs as “huge fireballs heading toward Earth at top speed.”

On July 16, a CME started at 13:08 GMT but changed course mid-journey, ultimately missing Earth. Although this event had no impact, solar storms, solar flares, and CMEs regularly affect Earth’s weather and nearly 7,800 satellites in orbit.

CMEs rarely endanger human life directly but can severely affect satellite electronics and power grids. These events also cause auroras near the poles and, during intense storms, can create auroras visible as far south as London or Paris. The more severe impact occurs in space, where CMEs disrupt satellite systems and communication services.

Prof. Ramesh emphasized the threat to communication satellites, warning that a CME could knock out internet, phone, and radio services. The Carrington Event of 1859, the strongest solar storm on record, disrupted telegraph systems worldwide. In 2012, a similarly powerful CME narrowly missed Earth, underscoring the ongoing risk.

Protecting Earth from Solar Storms

Recent history shows the disruptive power of solar storms. In 1989, a CME knocked out Quebec’s power grid, cutting electricity for six million people for nine hours. In 2015, solar activity caused air traffic control disruptions at European airports, delaying numerous flights.

By studying the Sun in real time, scientists can now predict when CMEs or solar storms are headed for Earth. Early warnings allow for preemptive shutdowns of satellites and power grids to protect critical systems. Space agencies from NASA, ESA, Japan, and China have been monitoring solar activity for decades. India’s Aditya-L1 now joins this global effort to study the Sun from space.

Aditya-L1’s position in space enables continuous observation of the Sun, even during eclipses. While Earth-based observers can only see the Sun’s photosphere, Aditya-L1 provides a full view of the Sun’s outer corona. This region, usually visible only during total solar eclipses, is critical for studying CME formation.

India’s coronagraph offers a unique advantage over NASA-ESA’s Solar and Heliospheric Observatory (SOHO). Prof. Ramesh highlighted this edge, noting, “Our coronagraph blocks the photosphere, offering an uninterrupted view of the corona. This allows us to study CME origins in greater detail.” In contrast, SOHO’s coronagraph obscures parts of the corona, limiting its view of some CME formations.

With Aditya-L1, scientists can now track CME origins and paths more accurately. Data from Aditya-L1, combined with insights from India’s ground-based solar observatories in Kodaikanal, Gauribidanur, and Udaipur, will deepen understanding of solar behavior.

Aditya-L1’s groundbreaking work is a major step in predicting and mitigating the effects of solar storms. The knowledge gained from this mission will help protect Earth’s infrastructure and safeguard space-based technologies that support modern life.