Aditya-L1: Shedding Light on Coronal Mass Ejections and Space Weather

India’s maiden solar mission, Aditya-L1, equipped with the Visible Emission Line Coronagraph (Velc), has provided groundbreaking data that enabled scientists to determine the precise timing of a coronal mass ejection (CME). This advancement marks a significant step in understanding the Sun's dynamic behaviour.

Understanding Coronal Mass Ejections

CMEs are massive ejections of charged particles and magnetic fields from the Sun’s corona. They can weigh up to a trillion kilograms and travel at speeds of up to 3,000 km/s (1,864 miles/s), potentially reaching Earth in as little as 15 hours. “Imagine a giant fireball hurtling toward Earth at that speed,” explains Prof. R. Ramesh of the Indian Institute of Astrophysics, the lead designer of Velc.

Observing a CME Event

Velc captured a CME on July 16, 2024, originating on the Sun’s Earth-facing side at 13:08 GMT. However, within 30 minutes, it deflected and moved behind the Sun, avoiding any impact on Earth’s weather or space environment.

Effects of CMEs on Earth and Space

Solar storms, flares, and CMEs can disrupt Earth’s magnetic field, causing widespread effects:

Auroras: While they create stunning light displays like the aurora borealis and australis, strong CMEs can push auroras to unexpected locations, such as London and France.

Satellite Disruption: CMEs can damage satellite electronics, disrupt power grids, and interfere with communication systems, leading to chaos.

Prof. Ramesh highlights the importance of satellites in modern life: “A strong CME could trip the internet, phone lines, and radio communication, resulting in absolute chaos.”

Historical Solar Events

The Carrington Event (1859): The most intense solar storm recorded, it caused global telegraph disruptions and vivid auroras.

2012 CME Near Miss: Earth narrowly avoided a storm of similar magnitude, which passed by NASA’s STEREO-A observatory instead.

1989 Quebec Blackout: A CME disabled Quebec’s power grid for nine hours, affecting six million people.

2015 Air Traffic Disruption: Solar activity caused significant delays across European airports, affecting air traffic control.

Mitigating Solar Storm Effects

Real-time solar monitoring is essential to mitigate the impact of CMEs. Timely warnings allow authorities to safeguard satellites and temporarily shut down power grids, minimising damage.

India’s Solar Observations: A New Era

Aditya-L1’s continuous solar observations, even during eclipses, provide unparalleled insights into solar activity. Velc’s innovative design allows it to mask the Sun’s photosphere and focus solely on the corona, making it superior to the coronagraph aboard the NASA-ESA Solar and Heliospheric Observatory.

“With Velc, we can precisely determine when a CME begins and its trajectory,” says Prof. Ramesh, emphasising its importance in early warning systems.

Ground-Based Support

India complements Aditya-L1 with three ground-based observatories in Kodaikanal, Gauribidanur, and Udaipur, which enhance the understanding of solar activity through real-time observations.

Preparing for Space Weather

Aditya-L1’s data is crucial for predicting and mitigating the effects of space weather on Earth. By contributing valuable insights to global solar research, India is enhancing humanity’s ability to prepare for and respond to potential solar threats.

This mission solidifies India’s position as a key player in the study of the Sun, offering tools to better understand and manage the impact of solar activity on our interconnected world.