Context: A solar eclipse (Surya Grahan) is scheduled to occur on 14th October 2023. It will be visible in the western hemisphere.

Demystifying Solar Eclipses: Causes and Shadows

• Solar eclipse (Surya Grahan)  is an astronomical event where the Moon passes between Earth and the Sun, obscuring the view of the Sun from a small part of the Earth, either completely or partially.
• How Solar Eclipses (Surya Grahan) Occur?
  • Sun, Moon, and Earth Alignment: For solar eclipse to occur, the moon must pass between the Earth and the Sun, which temporarily blocks out the sunlight.
  • Role of Moon’s Orbit: Such event occurs approximately every six months during the new moon phase as during this time orbital plane of Moon is closest to the plane of the Earth’s orbit.

• What Causes the Shadow on Earth?
  • Two types of shadows are cast on the Earth by the Moon during solar eclipse (Surya Grahan)
  • The Umbra: The Umbra is the dark center of the Moon’s shadow. People within the umbra will be able to witness a total eclipse. The Umbra gets smaller as it reaches Earth.
  • The Penumbra: The Penumbra is the outer part of the Moon’s shadow and gets larger as it reaches Earth. People within the penumbra will witness a partial eclipse.

•  Phases of a Solar Eclipse (Surya Grahan)

Different Types of Solar Eclipses (Surya Grahan): From Annular to Total and More

• Annular Solar Eclipse: Annular solar eclipse or Ring of Fire takes place when the Moon comes between the Sun and Earth while it is at its farthest point from Earth.
  • The Moon looks smaller than the Sun as it is at its farthest point and hence does not cover the Sun completely.
• Total Solar Eclipse (Surya Grahan): This phenomenon occurs when the Moon completely blocks out the Sun. As a result, the sky will darken completely.
• Hybrid Solar Eclipse: It is a combination of total and annular eclipse. At some points on Earth, it appears as a total eclipse, whereas at other points it appears as annular.
• Partial Solar Eclipse: This phenomenon occurs when the Sun and Moon are not exactly in line with the Earth, and the Moon only partially covers the Sun.
  • However, partial eclipses are hardly noticeable as it requires 90% coverage of the Sun to notice any darkening.

The Scientific Impact of Solar Eclipses (Surya Grahan) on Earth and Beyond

• Study Temperature Variation: Temperature drop during an eclipse can lead to cooling of the upper atmosphere.
  • This event is likely to affect the temperature structure of the ionosphere.
• Radio Frequency Variation: Electron density in the ionosphere will decrease due to cooling in the ionosphere.
  • This will have an impact on propagation of radio waves, particularly of high frequency.
• Satellite Communication Challenges: Anomalies in the ionosphere will impact satellite-based navigation signals and also communication.
• Studying Environmental Changes: Studies have shown that solar eclipses (Surya Grahan) can alter Earth’s temperature, relative humidity, wind speed and also ozone density.
• Helps in Solar Studies: Eclipses of the Sun allow scientists to study the Sun’s atmosphere called the corona, which otherwise is not possible due to the bright light of the Sun.

How Solar Eclipses (Surya Grahan) Shaped Celestial Understanding

• Contributions to Understanding Celestial Mechanics
  • Chinese: The Chinese constructed sophisticated observatory buildings for viewing solar eclipses (Surya Grahan). There were astrologers to predict the Emperor’s future using observations.
  • Greek Culture:  Greek astronomers made observations during eclipses and proposed the first known heliocentric model of the Universe.

Solar Eclipses (Surya Grahan) Across Cultures: Spiritual, Artistic, and Historical Significance

• Indian Culture:
  • Evidence: The oldest reference of Eclipse in India is in the Rig Veda that describes the effect of eclipse.
  • Means of Attaining Salvation: Skanda Purana has a legend where sages witness a forest-dwelling woman transform into a beauty after bathing in a holy lake during a solar eclipse (Surya Grahan), implying that it is a way of attaining salvation.
  • Ancestral Duties: According to Padma Purana, a man who offers water to his ancestors during a solar eclipse (Surya Grahan) achieves heaven. However, he becomes a Chandala in case of failure to do so.
• Influence on Art, Literature, and Religion
  • Art: Eclipse has been portrayed in paintings as a monster, dragon, and even a celestial dog, swallowing the sun in ancient Maya and Chinese culture.
    • They were used in the backdrop of European Renaissance crucifixion scenes to give a sorrowful effect.
  • Literature: In Homer’s Odyssey, the protagonist returns to his kingdom, accompanied by a seer’s vision of an eclipse.
• Egyptian Culture: In ancient Egypt, the King who saw himself as a representative of the Sun went around the city to reassure people.
• Chinese Culture: Chinese considered eclipses to be omens that predicted the future of the Emperor, and hence was important to predict eclipses.

Legends Surrounding Solar Eclipses (Surya Grahan): A Global Perspective

• India:  According to Hindu mythology, the severed head of Rahu flies off into the sky and swallows the Sun causing an eclipse.
• Vietnam: Vietnamese believe that the eclipse is caused by a giant frog devouring the Sun.
• Norse Culture: According to ancient Norse culture, the eclipse is caused due to the wolf devouring the Sun.
• Korea: The Koreans believe that the solar eclipse (Surya Grahan) is caused due to mythical dogs trying to steal the Sun.
• Greeks: Ancient Greek people believed that the solar eclipse was a sign of angry gods and that it signaled the beginning of disasters and destruction.

Myths and Superstitions Surrounding Solar Eclipses (Surya Grahan) Worldwide

• Myths in India:
  • Food Consumption: Eating food during the eclipse period can cause illness. It is advised to observe fasting during the course of the event.
  • Reducing Effects: Feeding cows and reciting holy mantras can help one overcome the negative effects of solar eclipse (Surya Grahan).
  • Avoiding Apples: Pregnant women are advised to avoid cutting apples else the baby may be born without fingers.
  • Adding Tulsi Leaves to Food: Tulsi leaves have to be added to cooked food to remove all the ill effects and stop bacterial growth post eclipse.
• Myths Across the World:
  • Signs of Bad Events: People around the world see eclipses as evil omens that bring death, destruction, and disasters.
  • Impact on Women and Children: Popular misconception is that solar eclipse (Surya Grahan) can endanger pregnant women and their unborn children.
  • Brighter Flowers: Italians believe that flowers planted during a solar eclipse are brighter and colorful than those planted any other time of the year.

Conclusion

• Solar eclipses (Surya Grahan) are astronomical events that have both scientific and cultural significance. They can impact Earth’s atmosphere, temperature, and wildlife. They have also shaped celestial understanding and influenced art, literature, and religion across cultures.