India’s first scientific mission dedicated to studying the Sun, the Aditya-L1, has released its first significant scientific findings. The mission, developed by the Indian Space Research Organisation (ISRO), aims to enhance our understanding of solar phenomena, particularly Coronal Mass Ejections (CMEs).

Aditya-L1

• Aditya-L1 was launched on September 2, 2023, from the Satish Dhawan Space Centre in Sriharikota. 

• The mission’s primary payload, the Visible Emission Line Coronagraph (VELC), was developed by the Indian Institute of Astrophysics (IIA) in Bengaluru. 

• Aditya-L1 is the first space-based observatory class Indian solar mission to study the Sun.

• The spacecraft completed its first halo orbit around the Sun-Earth L1 point on July 2, 2024.

• The Lagrange Point 1 (L1) of the Sun-Earth system is approximately 1.5 million km away from the Earth, which is about 1 per cent of the Earth-Sun distance.

• A satellite placed in the halo orbit around the L1 point has the major advantage of continuously viewing the Sun without any occultation/eclipse. 

• This will provide a greater advantage of observing the solar activities continuously. 

• The spacecraft carries seven payloads to observe the photosphere, chromosphere, and the outermost layers of the Sun (the corona) using electromagnetic and particle detectors.

• Using the special vantage point of L1, four payloads directly view the Sun and the remaining three payloads carry out in-situ studies of particles and fields at the Lagrange point L1.

• The instruments of Aditya-L1 are tuned to observe the solar atmosphere, mainly the chromosphere and corona, while the in-situ instruments will observe the local environment at L1.

• The payloads are expected to provide most crucial information to understand the problems of coronal heating, Coronal Mass Ejection, pre-flare and flare activities, and their characteristics, dynamics of space weather, study of the propagation of particles, and fields in the interplanetary medium, etc.

Unique observations of CMEs

• Coronal Mass Ejections (CMEs): The Sun frequently experiences violent eruptions known as CMEs, which release vast quantities of plasma. These phenomena can have significant effects on Earth, potentially damaging satellites and disrupting communication networks. 

• Precision Monitoring: VELC allows for unique observations of CMEs as they develop, offering insights into their characteristics and the conditions on the solar surface from which they originate. This capability was previously unavailable, as CMEs were typically only observed once they moved away from the Sun. 

• Scientific Goals: One of VELC’s major goals is to monitor CMEs and study their plasma properties. 

• Increasing Solar Activity: With the Sun nearing the peak of its solar cycle (Cycle No. 25), an increase in CME occurrences is anticipated. Continuous monitoring with VELC is expected to yield valuable data on these energetic eruptions. 

Importance of VELC observations

The ability to observe CMEs close to the solar surface allows scientists to gather crucial information about the thermodynamic properties of these eruptions:

• Understanding Source Regions: By studying CMEs at their origin, researchers can better understand the conditions that lead to their formation, which is essential for predicting their behavior and potential impacts on Earth. 

• Impact on Technology and Society: Insights gained from VELC’s observations can help mitigate the effects of CMEs on technology and infrastructure, enhancing our preparedness for solar storms.

(The author is a trainer for Civil Services aspirants.)