Knowledge Nugget: Why is solar flare ‘kernel’ important for UPSC?

Key Takeaways:

The solar flare ‘kernel’ was detected by the Solar Ultraviolet Imaging Telescope (SUIT) on board the Aditya-L1 mission observed an X6.3-class solar flare on February 22, 2024, one of the most intense categories of solar eruptions. The uniqueness of this discovery lies in the fact that SUIT detected brightening in the near ultraviolet wavelength range (200-400 nm).

Understanding the solar cycle and the reason for the increase in solar missions

1. According to the National Oceanic and Atmospheric Administration (NOAA), the present solar activity and number of sunspots suggest that the solar cycle may be nearing its maximum, though the official confirmation of the same is yet to be made.

2. Scientists believe that the solar maximum is the best possible window available to both launch and observe the sun. This is precisely why there has been a spike in the missions to observe the star. Solar physicists are well aware if they miss this window, the next possible intense solar activity will not be before 2035-2036.

NASA’s Solar Dynamics Observatory captured this image of a solar flare – as seen in the bright flash in the upper right, in 2023. (NASA/SDO)

3. Solar cycle: The sun has a magnetic field with north and south poles similar to a bar magnet. The magnetic field exists due to the constant movement of electrically charged particles within the Sun. Every 11 years or so, the Sun’s magnetic field completely flips, meaning its north and south poles switch places. This periodic change is known as the solar cycle.

4. Solar maximum: This solar cycle affects the activity on the surface of the Sun. For instance, the Sun is at its most active when the magnetic field flips. This phase is called the solar maximum. During this period, the star can send out more frequent and intense bursts of radiation and particles into space. After the flip, the star calms down until it reaches the solar minimum, and a new cycle begins.

5. The solar maximum impacts the number of sunspots. The number of sunspots—  small, dark, and cooler areas where the magnetic field is particularly strong, is highest during the solar maximum and least during the solar minimum. Scientists track the solar cycle by counting the number of sunspots.

6. Solar flares and CME: During the solar cycle, the solar flares and coronal mass ejections (CME) increase. Solar flares release huge bursts of radiation and energetic particles by sudden release of magnetic energy stored in the complex solar magnetic field. In CMEs, the sun throws out large amounts of plasma and magnetic fields.

7. Impact: Such events can have a serious impact on space weather and geo-space, including disrupting radio communications, affecting satellite operations, interfering with power grids, and posing risks to astronauts and airline passengers.

BEYOND THE NUGGET: Solar Missions

Since solar maxima are the best windows to study the sun, three major solar missions have been launched.

1. Aditya-L1 Mission: It was India’s first solar mission, launched on September 2, 2023, with the objective of expanding our knowledge of the Sun and how its radiation, heat, particle flow, and magnetic fields affect us. The mission had seven payloads. Two important payloads are the Visible Emission Line Coronagraph (VLEC) and the Solar Ultraviolet Imaging Telescope (SUIT).

2. Proba-3: It was launched by the European Space Agency on December 5, 2024, through ISRO’s PSLV-C59 vehicle. This is the first-ever attempt at “precision formation flying”, where two satellites will fly together and maintain a fixed configuration in space.

Depiction of how the Occulter Spacecraft will cast a precise shadow across the Coronagraph spacecraft. (Image source: ESA)

The two satellites — Occulter Spacecraft (weighing 200 kg) and the Coronagraph Spacecraft (weighing 340 kg) — will mimic a natural solar eclipse. They will manoeuvre precisely in Earth’s orbit so that one satellite casts a shadow onto the other.

3. PUNCH Mission: NASA’s Punch Mission was launched on March 11, 2025. According to the official website of nasa, the Punch mission uses four suitcase-sized satellites to observe the Sun and its environment. Working together, the four PUNCH satellites will create a combined field of view and map the region where the Sun’s corona (or outer atmosphere) transitions to the solar wind (the constant outflow of material from the Sun).

Post read question

If a major solar storm (solar flare) reaches the Earth, which of the following are the possible effects on the Earth? (UPSC CSE 2022)

1. GPS and navigation systems could fail.

2. Tsunamis could occur at equatorial regions.

3. Power grids could be damaged.

4. Intense auroras could occur over much of the Earth.

5. Forest fires could take place over much of the planet.

6. Orbits of the satellites could be disturbed.

7. Shortwave radio communication of the aircraft flying over polar regions could be interrupted.

(a) 1, 2, 4 and 5 only

(b) 2, 3, 5, 6 and 7 only

(c) 1, 3, 4, 6 and 7 only

(d) 1, 2, 3, 4, 5, 6 and 7

(Source: NASA’s PUNCH set to lift off, Capturing unprecedented details of solar flares with Solar Ultraviolet Imaging Telescope, Knowledge nugget of the day: Proba-3 Mission, Sun throws out strongest explosion in years on a day full of solar flares)

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