Context:
On April 8 2024, a total solar eclipse crossed North America, passing over Mexico, the United States, and Canada.
What is a solar eclipse?
- A solar eclipse takes place when the Moon moves in the middle of Earth and the Sun.
- The Moon blocks the light of the Sun, either fully or partially, which casts a huge shadow on some parts of the world.
4 types of solar eclipses
Total Solar Eclipse:
- When the Moon blocks the Sun entirely, the areas in the centre of the Moon’s shadow at the time witness a total solar eclipse.
- A full solar eclipse, known as totality, is almost as dark as night.
- A glimpse of the Sun’s corona (Sun’s outer atmosphere) is visible [usually not visible due to the bright face of the Sun].
- At Maximum point of the eclipse (midpoint of time of totality), the sky goes dark and temperatures can fall.
Diamond Ring Effect:
- Baily’s beads effect, or Diamond ring effect – A feature of total and annular solar eclipses.
- As the moon goes by the Sun during a solar eclipse, the lunar limb topography allows beads of sunlight to shine through in some places, and not in others.
- The effect is caused due to the rugged lunar surface.
- The diamond ring effect is seen when only one bead is left, a shining diamond set in a bright ring around the lunar silhouette.
- Diamond ring is observed during solar eclipse, only along the peripheral regions of the totality trail.
Annular Solar Eclipse:
- When the Moon passes in front of the Sun but is at or near the farthest point from Earth, an annular solar eclipse occurs.
- As the Moon is far away from Earth, it appears smaller than the Sun and does not completely cover the Sun.
- Moon covers the Sun in such a way that only the periphery of the Sun remains visible — looking like a ring of fire.
Partial Solar Eclipse:
- A partial solar eclipse takes place when the Moon blocks just a part of the Sun, giving it a crescent shape.
- During both partial and annular eclipses, the regions outside the area covered by the Moon’s umbra — the middle and the darkest part of the lunar shadow — will see a partial solar eclipse.
- Most common type of solar eclipse.
Hybrid Solar Eclipse:
- Rarest type of solar eclipse
- It is witnessed when an eclipse shifts between annular and total as the shadow of the Moon moves across the globe.
- In this case, some parts of the world see a total solar eclipse, while others observe an annular solar eclipse.
How often does a solar eclipse take place?
- A solar eclipse is witnessed only during the new moon (when the Moon and Sun are aligned on the same side of Earth).
- A new moon occurs about 29.5 days but, however, does not mean that a solar eclipse happens every month. It takes place only between 2 to 5 times annually.
- It is because the Moon does not orbit Earth in the same plane as the Earth orbits the Sun. In fact, the Moon is tilted by about five degrees with respect to Earth.
- As a result, most of the time when the Moon is in between the Sun and Earth, its shadow is either too high or too low to fall on the Earth.
Total solar eclipses only happen about once every 18 months or so. Why?
- This is because a total eclipse is only visible if one is standing in the umbra — the other part of the shadow is called the penumbra, which is not as dark as the umbra.
- The umbral shadow is very small, covering only a small part of Earth.
- In fact, the entire path of the umbral shadow during a solar eclipse will only cover less than one per cent of the globe. This is why only very few people will get to see a total eclipse at a time.
- Moreover, about 70 per cent of the globe is underwater and half of the land is considered uninhabited.
Source: Indian Express
Previous Year Question
The term ‘Goldilocks Zone’ is often seen news in the context of
[UPSC Civil Services Exam – 2015 Prelims]
(a) the limits of habitable zone above the surface of the Earth
(b) regions inside the Earth where shale gas is available
(c) search for the Earth-like planets in outer space
(d) search for meteorites containing precious metals
Answer: (c)
