India’s budding space exploration program took a major step forward with the recent launch of Aditya-L1, India’s first-ever solar mission. Aditya-L1 was launched into orbit last year. It has recently begun providing extremely valuable information about solar activity – particularly Coronal Mass Ejections (CMEs). This exciting mission is carrying seven cutting-edge scientific instruments. Its mission is to provide a better understanding of the Sun and its role in influencing space weather.
One of the flagship instruments on Aditya-L1 is the Visible Emission Line Coronagraph (Velc). One of the observatory’s most important tasks is monitoring solar activity. Prof. R Ramesh, Velc’s principal investigator, is leading the mission’s research endeavors. The coronagraph’s design allows it to very effectively recreate the Moon’s appearance. This ingenious piece of design circumvents the Sun’s photosphere too, allowing for an unbroken view of the corona throughout the year – even during eclipses.
Aditya-L1 has already made some amazing observations, including data collected from one of the largest CMEs ever recorded. This particular CME originated on September 13, 2024, at 00:30 GMT, and exhibited remarkable characteristics. At its source, the temperature reached a staggering 1.8 million degrees Celsius. It carried a payload of prodigious energy content equal to 2.2 million megatons of TNT and weighed an incredible 270 million tonnes.
It’s no surprise, then, that studying CMEs is one of the core scientific objectives of Aditya-L1. These enormous solar explosions can cause these gigantic geomagnetic storms, and they wreak havoc on satellites and other technologies in near-Earth space. Almost 11,000 satellites are now orbiting our blue planet, including 136 from India. Every single one of these satellites is at risk for damage from coronal mass ejections (CMEs).
Prof. Ramesh noted the dual nature of CMEs, stating, “The most beautiful manifestations of a CME are auroras, which are a clear example that charged particles from the Sun are travelling to Earth.” He cautioned about their potential hazards: “They can make all the electronics on a satellite malfunction, knock down power grids and affect weather and communication satellites.”
As the Sun approaches its maximum activity cycle, Aditya-L1 will be strategically positioned to observe CMEs with energy contents reaching up to 100 million megatons. Prof. Ramesh remarked on the significance of this timing: “I consider the CME we evaluated to have occurred when the Sun was in the normal activity phase. Now this sets the benchmark that we’ll be using to evaluate what is in store when the maximum activity cycle occurs.”
According to them, Aditya-L1 will offer invaluable input that aids creation of countermeasures to safeguard satellites. Along the way, it will help us calibrate our models of how near-Earth space works. Prof. Ramesh emphasized this point by stating, “The learnings from this will help us work out the countermeasures to be adopted to protect satellites in near space. They will help us gain a better understanding of near-Earth space.”
Alongside tracking these bigger CMEs, Aditya-L1 is still hard at work observing all the usual solar activity. When solar activity is at a normal or low level, the Sun usually sends off two to three CMEs per day. As solar activity continues to increase, having a better handle on these phenomena will be critical to protecting our technological infrastructure.