India‘s ambitious Sun mission, Aditya-L1, has successfully reached its final destination, marking a significant milestone in the nation’s space exploration efforts. Launched last year, this mission is now poised to enhance understanding of solar activities, particularly coronal mass ejections (CMEs), which can have profound effects on Earth’s space environment.
Aditya-L1 is carrying a set of seven scientific instruments, among which the Visible Emission Line Coronagraph (Velc). This cutting-edge instrument was built exclusively to study the Sun’s corona, recording live information on solar storms and CMEs. The mission’s capabilities were recently showcased when it recorded one of the largest CMEs to date, a powerful event that serves as a reminder of the Sun’s dynamic nature.
The CME recorded by Aditya-L1 carried a mind-boggling energy equivalent of 2.2 million megatons of TNT. This extraordinary power was released from a searing heat of 1.8 million degrees Celsius. This CME is approximately the size of 270 million tonnes. It poignantly illustrates the massive scale of solar activity that can impact satellites in orbit and technology here on Earth.
Aditya-L1 is thus ideally placed to passively observe the Sun at its peak activity. It won’t be unusual to see ten or more coronal mass ejections (CMEs) per day. These frequent solar events can suddenly change geomagnetic conditions within near-Earth space. This creates hazards to almost 11,000 satellites already in orbit, including 136 from India. CMEs are known to create widespread havoc in air traffic control by blinding air traffic personnel with limited ability to detect aircraft. Sometimes, they even trigger collapses of entire power grids like the 1989 Quebec failure, which cut power to six million people for nine hours.
Prof. R Ramesh from the Indian Institute of Astrophysics, a co-pi of the mission, added how important it is to study these solar phenomena. He illustrated how CMEs produce amazing auroras, a pretty way to see charged particles from the Sun coming to Earth. They can cause major destruction on the ground, frying satellite electronics and taking down power grids.
“But they can also make all the electronics on a satellite malfunction, knock down power grids and affect weather and communication satellites.” – Prof Ramesh
Shedding more light on CMEs is one of the primary science goals for Aditya-L1. The mission aims to establish benchmarks for evaluating solar activity during normal phases and prepare for the anticipated effects during peak activity times.
“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
This is why the Velc coronagraph is central to this research. Its shape is designed to match the size of the Moon, completely covering the Sun’s photosphere. This produces an uninterrupted, scientifically important view of the corona year-round, including during eclipse events. This unprecedented new capability enables scientists to continuously observe these solar phenomena, greatly increasing the value of the data collected.
“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, even during eclipses and occultations,” – Prof Ramesh
During quiet periods, or when the Sun is less active, it can be expected to erupt two or three CMEs each day. As Aditya-L1 takes active observations of the cosmos. Its discoveries will advance our scientific knowledge and inform solutions that protect satellites in near-space.
“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
Aditya-L1 combines cutting-edge technologies to transform our understanding of solar dynamics. Its singular focus is to uncover how these changing dynamics are affecting all life on Earth. The learnings will be instrumental in making sure we’re even better prepared for the next big solar event. It will protect technologies dependent on a stable space weather environment.
