Total Solar Eclipse And Solar Corona
Source: Indian Express
GS III: Science and Technology- Awareness in the field of Space
Overview
- A total solar eclipse occurs when the Moon passes between the Sun and Earth and completely covers the Sun’s disc for observers within the path of totality.
- It requires a New Moon near an orbital node, as the Moon’s orbit is inclined by about 5° to Earth’s orbital plane.
- Totality allows clearer observation of the solar corona, helping researchers study its structure and magnetic activity.
- Understanding solar activity improves knowledge of events such as solar flares and CMEs, which can affect satellites, GPS and communication systems.
Why in the News?
A total solar eclipse was visible across parts of Europe on August 12–13, 2026, providing scientists an opportunity to study the Sun’s corona and magnetic activity under natural observing conditions.
News in Brief
- Its path of totality crossed Greenland, Iceland, Northern Russia, Spain, and a small part of Portugal, bringing brief daytime darkness.
- A partial eclipse was visible across much of North America, Europe, and Northwest Africa.
- It was not visible in India because it occurred during local nighttime hours when the Sun was below the horizon.
What is a Total Solar Eclipse
- A solar eclipse occurs when the Moon passes between the Sun and Earth and blocks sunlight from reaching parts of the Earth.
- In a total solar eclipse, the Moon completely covers the Sun’s disc for observers located within the narrow path of totality.
- The eclipse is not visible in the same way from every location.
- While some places experience complete darkness for a short period, others may see only a partial eclipse or experience little noticeable change in daylight.
- The path where totality can be observed is called the path of totality.
- The duration of totality depends on factors such as the relative positions of the Sun, Moon and Earth and the location of the observer.
Types of Solar Eclipses
- Total Eclipse- The Moon appears large enough to completely cover the Sun’s disc, revealing the solar corona.
- Partial Eclipse- The Moon covers only a part of the Sun because the observer is within the penumbral shadow.
- Annular Eclipse- The Moon is farther from Earth and appears smaller, leaving a bright “ring of fire” around the Sun.
- Hybrid Eclipse- A rare eclipse that appears total from some locations and annular from others, mainly due to the curvature of Earth and the changing geometry of the Moon’s shadow.
Solar Corona
- The corona is the outermost layer of the Sun’s atmosphere.
- It extends millions of kilometres into space and is extremely hot, but it is much fainter than the Sun’s visible surface.
- Normally, the intense brightness of the solar disc makes it difficult to observe the corona from Earth.
- During a total eclipse, however, the Moon blocks the bright disc and the corona appears as a glowing halo around it.
- Scientists study this region because the corona contains clues about the Sun’s magnetic activity.
- Changes in its magnetic structures are associated with solar flares and coronal mass ejections (CMEs).
Solar Activity and Earth
- The Sun does not remain equally active all the time.
- Its activity follows an approximately 11-year solar cycle, marked by changes in sunspots, solar flares and other phenomena.
- During periods of high activity, powerful solar eruptions can release large amounts of charged particles and electromagnetic radiation.
- When these interact with Earth’s magnetic environment, they can produce space weather events.
- Strong space weather can interfere with satellite operations, radio communication and GPS signals.
- It can also create additional risks for spacecraft and, in extreme cases, affect power infrastructure.
When and How Solar Eclipses Occur
- New Moon- A solar eclipse can occur only during the New Moon, when the Moon comes between the Sun and Earth.
- Orbital Alignment- The Moon’s orbit is tilted by about 5° relative to Earth’s orbit around the Sun. Therefore, an eclipse occurs only when the New Moon is near an orbital node, where the two orbital planes intersect.
- Shadow Formation- The type of eclipse depends on which part of the Moon’s shadow reaches Earth,
- Umbra– Complete shadow → Total eclipse
- Penumbra– Partial shadow → Partial eclipse
- Antumbra– Extended shadow beyond the umbra → Annular eclipse.
UPSC Prelims and Mains Practice Question
Consider the following statements regarding solar eclipses:
- A solar eclipse can occur only during the New Moon phase.
- A total solar eclipse occurs when the observer is located within the Moon’s penumbral shadow.
- An annular eclipse occurs when the Moon appears smaller than the Sun and leaves a bright ring around it.
- A hybrid eclipse can appear total from some locations and annular from others.
Which of the statements given above are correct?
A. 1 and 2 only
B. 1, 3 and 4 only
C. 2, 3 and 4 only
D. 1, 2, 3 and 4
Answer: B. 1, 3 and 4 only
Mains Practice Question
Q. Solar eclipses are not merely astronomical phenomena but also provide valuable opportunities for scientific research. Explain the conditions necessary for a solar eclipse and discuss the significance of studying solar eclipses and their impact on Earth. (150 Words)
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