Aditya-L1 Makes History: India’s First Visible-Light Spectroscopic Observation of a CME

• Recently, scientists from the Indian Institute of Astrophysics (IIA), in collaboration with NASA, made a remarkable discovery using data from the Visible Emission Line Coronagraph (VELC) aboard Aditya-L1 — India’s first solar mission.
• They successfully tracked a Coronal Mass Ejection (CME) and estimated its important physical properties such as speed, density, and temperature.
• This marks the first-ever visible-light spectroscopic observation of a CME in history.
  • Spectroscopic observation means studying light from an object to learn about its composition, motion, and temperature by analyzing how light is emitted or absorbed.

What Exactly Are Coronal Mass Ejections (CMEs)?

• Coronal Mass Ejections (CMEs) are massive explosions of plasma (hot, electrically charged gas) and magnetic fields from the Sun’s corona, the outermost layer of the solar atmosphere.
• When CMEs travel toward Earth, they can cause geomagnetic storms that disturb the planet’s magnetic field, potentially affecting satellites, communication systems, GPS networks, and even power grids.
• That’s why tracking and understanding CMEs is crucial for predicting space weather — the changing conditions in space influenced by solar activity.

What Is the Aditya-L1 Mission?

• Aditya-L1 is India’s first dedicated mission to study the Sun, launched in 2023 by PSLV-C57.
• The mission is designed for a five-year lifespan and aims to improve our understanding of the Sun’s behavior and its impact on the near-Earth environment.

Where Is Aditya-L1 Located and Why Is That Important?

• The spacecraft is positioned in a halo orbit around the Lagrange Point 1 (L1) of the Sun–Earth system.
• The L1 point, located about 1.5 million kilometers from Earth, is a region where the gravitational pull of the Sun and Earth balances the centripetal force needed for a spacecraft to move with them.
• Because of this balance, a spacecraft at L1 needs very little fuel to stay in position.
  A halo orbit is a three-dimensional loop around this point, allowing Aditya-L1 to continuously observe the Sun without any obstruction from Earth’s shadow.

What Are the Main Objectives of Aditya-L1?

The mission aims to explore several key scientific questions about the Sun:

• Why is the corona (outer layer) of the Sun hotter than its surface? (known as the coronal heating problem)
• How is the solar wind — a stream of charged particles flowing from the Sun — accelerated?
• What causes solar flares, and how do they affect space weather near Earth?
• How does the temperature of solar wind plasma vary in different directions (called temperature anisotropy)?

What Instruments Does Aditya-L1 Carry to Study the Sun?

Aditya-L1 carries seven scientific payloads (instruments), designed to study different layers and phenomena of the Sun. These are divided into two types:

1. Remote Sensing Payloads – Directly observe the Sun

• VELC (Visible Emission Line Coronagraph): Studies the solar corona and Coronal Mass Ejections.
• SUIT (Solar Ultraviolet Imaging Telescope): Captures ultraviolet images of the Sun.

2. In-situ Payloads – Measure conditions at the spacecraft’s location

• ASPEX (Aditya Solar Wind Particle Experiment): Studies particles in the solar wind and their behavior.

Among these, VELC played the central role in observing and analyzing the recent CME event.

Why Is This Observation Scientifically Important?

• The successful spectroscopic measurement of a CME using VELC demonstrates India’s advancing expertise in solar spectroscopy and space weather forecasting.
• Such research helps improve early warning systems for solar storms, which can protect satellites, navigation networks, astronauts, and critical electrical infrastructure on Earth.

How Does Aditya-L1 Compare with Other Global Solar Missions?

Aditya-L1 joins a group of pioneering international missions dedicated to studying the Sun, including:

• Hinotori (ASTRO-A) – Japan’s early solar observation mission launched in the 1980s.
• Parker Solar Probe (NASA, 2018) – The first spacecraft to actually “touch the Sun” by entering its outer atmosphere.
• SOHO (Solar and Heliospheric Observatory) – A NASA–ESA joint mission and the longest-operating Sun-watching satellite.

What Does This Mean for the Future?

• The success of Aditya-L1 and its VELC instrument marks a major step forward for India’s space science and solar research.
• By observing the Sun in unprecedented detail, the mission not only deepens our understanding of solar activity but also helps make space weather forecasting more accurate — ensuring safer satellites, communications, and space missions in the years ahead.