Eclipses in mythology

Before science enlightened mankind, natural events were explained by supernatural beliefs, folklore and legends. Volcanoes rumbled when the mountain god was angry. Droughts were remedied with prayers to the rain god. You get the idea.

Solar eclipses were no different.

The ancient Chinese believed eclipses were caused by a mystical dragon in the sky eating up the Sun. (Though one superstition has it as a celestial dog eating up the Sun.) Which explains the Chinese word for a solar eclipse, which is 日食 (re shi), meaning “sun eat”.

When solar eclipses occurred in ancient China, people would come out and make a great noise and create a commotion by banging on pots and drums, lighting firecrackers to create a ruckus, or even shooting arrows into the sky, all in an effort to frighten away the dragon.

The idea of a monster, beast or demon devouring the Sun is a recurring one and can also be found in other cultures.

The Incas believed that a mythical feline called the Ccoa or K’owa whose tail swept the clouds producing hail, storm and rain. It was an active, angry spirit that caused solar eclipses, or Inti Jiwaña, and lunar eclipses as well. Like the Chinese, the Incas tried to intimidate the feline to prevent it from eating the Sun.

According to Hindu mythology, a solar eclipse represented the demons Rahu and Ketu locked in combat. As the legend goes, Rahu had slipped among the gods as they drank the divine nectar that granted immortality. However, before the nectar passed down his throat, Mohini, an avatar of Vishnu, cut off Rahu’s head, which continued to be immortal.

Astronomically, Rahu and Ketu represent the two points of intersection of the paths of the Sun and the Moon as the move through the celestial sphere. This leads to the belief that when the sun “disappears”, Rahu is believed to have swallowed it.

In ancient Egypt, sun cults refer to the myth of the serpent Apep swallowing the Sun God, Ra. However, some Egyptian legends also make reference to an eclipse occurring when a great hawk tries to steal Ra’s glory.

Comparing a Solar Eclipse to a Lunar Eclipse

Pictures help explain things better so here are two diagrams below to demonstrate how a solar eclipse compares to a lunar eclipse. Hope things are clear as day after this.

Solar Eclipse

Lunar Eclipse

What are Lunar Eclipses then?

The Sun isn’t the only object in the sky that gets eclipsed. The Moon can experience an eclipse too.

A solar eclipse occurs when the Moon passes between the Sun and the Earth, blocking the Sun from our view.

A lunar eclipse occurs when the Moon passes behind the Earth such that the planet blocks the Sun’s rays from striking the Moon. This happens when the Sun, Earth and Moon are aligned with the Earth in the middle.

Since the Moon doesn’t produce its own light, and that what we see in the nightsky is really the Moon reflecting light from the Sun, as it passes behind the Earth and into its shadow, the Moon becomes dark.

There are different types of lunar eclipses. Before we begin, the shadow of the Earth can be divided into two distinctive parts: the umbra and the penumbra. Within the umbra, there is no direct solar radiation. However, as a result of the Sun’s large angular size, solar illumination is only partially blocked in the outer portion of the Earth’s shadow, which is given the name penumbra.

• A penumbral eclipse occurs when the Moon passes through the Earth’s penumbra. The penumbra causes a subtle darkening of the Moon’s surface. A special type of penumbral eclipse is a total penumbral eclipse, during which the Moon lies exclusively within the Earth’s penumbra. Total penumbral eclipses are rare, and when these occur, that portion of the Moon which is closest to the umbra can appear somewhat darker than the rest of the Moon.

• A partial lunar eclipse occurs when only a portion of the Moon enters the umbra.

• When the Moon travels completely into the Earth’s umbra, one observes a total lunar eclipse. The Moon’s speed through the shadow is about one kilometer per second and totality may last up to nearly 107 minutes. Nevertheless, the total time between the Moon’s first and last contact with the shadow is much longer, and could last up to 3.8 hours. The relative distance of the Moon from the Earth at the time of an eclipse can affect the eclipse’s duration. In particular, when the Moon is near its apogee, the farthest point from the Earth in its orbit, its orbital speed is the slowest. The diameter of the umbra does not decrease much with distance. Thus, a totally-eclipsed Moon occurring near apogee will lengthen the duration of totality.

A different view of the eclipse

Imagine you were an astronaut on the International Space Station and an eclipse is happening. By not being on the surface of the Earth, there’s nothing to see, right?

Not really. The sight you’ll get is the shadow of the Moon on the surface of the Earth.

It’s similar to being on a plane and watching the patches of shadows caused by clouds falling on the countryside below.

Only in this case, the shadow is caused by the Moon. We’ve grown used to seeing events of epic size and  proportion in Hollywood blockbusters, but to give a little perspective on the scale of this: the Moon’s diameter is 3,474km, about a quarter of that of the Earth. Its surface area is that of North America and Russia combined.

That is some gigantic object blocking the Sun and creating the shadow.

If the sight of an eclipse is rare, this view of it seen from space has got to be rarer.

Photo: NASA

This eclipse was the one that took place on March 29, 2006 across Africa, the Mediterranean and parts of Asia Minor.