India’s foray into solar exploration has taken a giant leap forward with the successful launch of its first solar mission, Aditya-L1. This groundbreaking project made headlines recently when it captured what may be the largest coronal mass ejection (CMEs) ever. These giant eruptions can dramatically affect near-Earth space weather. The CME, which occurred on 13 September 2024 at 00:30 GMT, exhibited an energy content equivalent to a staggering 2.2 million megatons of TNT and originated from a region with temperatures soaring to 1.8 million degrees Celsius.
Aditya-L1’s most powerful instrument is the Visible Emission Line Coronagraph (Velc). Sciences employ it to further their understanding of solar dynamics. The Velc, described as the principal investigator’s most important instrument on the mission, operates by blocking the Sun’s intense brightness, akin to how the Moon obscures sunlight during an eclipse. This gives researchers the unique opportunity to continuously and precisely observe these faint outer corona of the Sun.
Coronal mass ejections can cause geomagnetic storms that can be hazardous to electrical and other technologies in near-Earth space. With almost 11,000 satellites now circling our planet—136 of which are Indian—the consequences of solar activity are significant. While CMEs have not killed any humans directly, their impact on humans can be felt when they disable satellites, power grids, and communication systems.
The primary goal of Aditya-L1’s mission is to track solar activity. It’s an opportunity to get us ready for the peak solar activity that’s forecasted to occur next year. Data obtained during this CME event will be helpful in building a greater understanding of solar behavior during periods of increased activity.
According to Prof. Ramesh, one of the topmost scientists associated with the mission, this CME was extremely important for future assessments.
“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,” – Prof Ramesh.
He added that combating CMEs is important, if we are to create countermeasures that could help satellites operating in the near-outer-space stay safe.
“The learnings from this will help us work out the countermeasures to be adopted to protect satellites in near space. They will also help us gain a better understanding of near-Earth space,” – Prof Ramesh.
Perhaps more importantly, he brought attention to the fact that CMEs are a key ingredient in solar dynamics.
“In the normal or low-activity times, the Sun launches two to three CMEs a day,” – Prof Ramesh.
Besides wreaking havoc, CMEs create beautiful natural occurrences such as auroras. These spectacular displays happen when high-energy particles emitted by the Sun collide with Earth’s magnetic field.
“The most beautiful manifestations of a CME are auroras, which are a clear example that charged particles from Sun are travelling to Earth,” – Prof Ramesh.
These same highly charged particles can cause widespread chaos by damaging satellite electronics and harming global navigation satellite systems’ communication capabilities.
“But they can also make all the electronics on a satellite malfunction, knock down power grids and affect weather and communication satellites,” – Prof Ramesh.
For instance, Aditya-L1’s coronagraph has been specially crafted to provide uninterrupted observations of the Sun’s corona, including during eclipses and occultations.
“Aditya-L1’s coronagraph is the exact size that lets it nearly mimic the Moon, fully covering the Sun’s photosphere and allowing it an uninterrupted view of almost all of the corona 24 hours a day, 365 days a year,” – Prof Ramesh.
This makes the present solar mission an extraordinary testament to India’s burgeoning space program. It promises to fundamentally improve our understanding of global solar phenomena. The collaboration between the Indian Institute of Astrophysics and NASA underscores the international effort to study and interpret solar activities for broader scientific benefit.
