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Aditya-L1 data help track which way solar eruptions travel

Scientists have used Doppler measurements from Aditya-L1's coronagraph to study how material moves in the Sun's corona during coronal mass ejections. This helps show which way an eruption is heading. Knowing the direction early matters because Earth-directed eruptions can disrupt satellites, communications and power grids.

Event date:

REq1
  1. Note1 / 4

    WHY IN NEWS?

    • Researchers used Doppler velocity data from the Visible Emission Line Coronagraph (VELC) on Aditya-L1 to study coronal mass ejections.
    • The measurements show whether solar plasma moves towards or away from the observer.
    • This adds the "depth" direction to the flat images that cameras record.
    • A recent study by the Indian Institute of Astrophysics analysed an eruption of 5 August 2024 and found it expanded unevenly sideways in the low corona.
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    ABOUT ADITYA-L1

    • India's first dedicated solar mission, launched on 2 September 2023 by PSLV.
    • It entered a halo orbit around the Sun–Earth L1 point in January 2024.
    • L1 is about 1.5 million km from Earth, towards the Sun.
    • It carries seven payloads: four look at the Sun, three measure particles and fields at L1.
    • VELC, its largest payload, was built by the Indian Institute of Astrophysics, Bengaluru.
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    KEY CONCEPTS

    1. What is a Lagrange point?

    It is a spot where the pull of two large bodies balances a spacecraft's motion. At L1, a craft stays between Earth and the Sun and watches the Sun without eclipses.

    1. What is a coronagraph?

    It blocks the Sun's bright disc to reveal the faint corona, the Sun's outer atmosphere. It creates an artificial eclipse.

    1. How does the Doppler effect reveal direction?

    Light from material moving away shifts to longer wavelengths, called redshift. Material moving towards us shifts to shorter wavelengths, called blueshift. Like a siren's pitch changing as it passes, the shift reveals motion.

    1. What is a coronal mass ejection?

    It is a huge burst of plasma and magnetic field from the Sun. If aimed at Earth, it can trigger geomagnetic storms.

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    WHY DIRECTION MATTERS

    • Satellites: Storms can damage electronics and increase drag on low-orbit satellites.
    • Communications and navigation: Radio and GPS signals can be disrupted.
    • Power grids: Strong storms can induce currents that damage transformers.
    • Early warning: Knowing an eruption's direction near the Sun gives more time to protect assets.

Sources

Syllabus

PaperSubjectSub-topic
GS3Science & TechnologyScience and Technology, space technology, achievements of Indians in science
PrelimsScience & TechnologyAditya-L1, Lagrange points, solar phenomena, Doppler effect

Topics

Information and Communication TechnologyPhysicsSpace Technology

Practice questions

  1. Aditya-L1 is placed in a halo orbit around:

    1. The Earth–Moon L2 point
    2. The Sun–Earth L1 point
    3. The Sun–Earth L2 point
    4. A geostationary orbit.
    Show answer

    Answer: B. L1 gives an uninterrupted view of the Sun, about 1.5 million km from Earth.

    Difficulty: medium · statement

  2. In solar observations, a redshift in an emission line indicates that the material is:

    1. Moving towards the observer
    2. Moving away from the observer
    3. Cooling rapidly
    4. Stationary.
    Show answer

    Answer: B. Motion away stretches the wavelength towards the red end.

    Difficulty: medium · statement

  3. The Visible Emission Line Coronagraph on Aditya-L1 was developed by:

    1. Physical Research Laboratory
    2. Indian Institute of Astrophysics
    3. Space Applications Centre
    4. IUCAA.
    Show answer

    Answer: B. VELC was built by the Bengaluru-based IIA.

    Difficulty: medium · statement

Mains practice

Answer-writing practice on this article. Attempt it first, then open the hints.

  1. GS3 · 150 words

    Explain the significance of space weather monitoring for India's space and terrestrial infrastructure. How does Aditya-L1 contribute to it?

    Show hints
    1. CMEs, geomagnetic storms
    2. satellites, GPS, power grids
    3. L1 vantage point
    4. VELC Doppler measurements, early warning