We explain what a solar eclipse is and why this phenomenon occurs. In addition, types of solar eclipse and precautions to see one.
What is a solar eclipse?
A solar eclipse is a phenomenon in which the Moon interposes between the Sun and the Earth , and can hide it in a total, partial or annular way depending on the size, location and distance between the stars.
On average, an eclipse of the Sun occurs every 18 months and lasts only a few minutes . The same total solar eclipse takes 400 years to repeat itself in the same place on the planet. This occurs because, like the movement of the Earth around the Sun, the Moon also moves over its elliptical orbit but around our planet.
When drawing an imaginary line that describes the translational movement of the celestial bodies, it is seen that the path of the orbit is oval. Therefore, depending on the section of the route, the Moon is closer or farther from Earth and these two in turn, more or less close to the Sun. This is the reason why they do not always align in the same way or At the same time of the year .
Why does a solar eclipse occur?
The movements of translation of the Earth and its natural satellite (the Moon), imply variations in the intensity of the shadow cast by the Moon on the planet at the time of the solar eclipse. The closer the Earth’s Moon is, the more intense and smaller in diameter its shadow is. Thus the concealment of the Sun occurs, that is, a total eclipse is visible only from the area where the shadow is cast . From other nearby regions, where only the penumbra of the Moon reaches, the same phenomenon is perceived as a partial solar eclipse.
To check this phenomenon in a simple way you can hold a ball between a lamp and a wall. As the ball approaches the lamp, the shadow it casts on the wall is bigger and softer. As the ball approaches the wall, the shadow has a smaller diameter and is more intense.
If the ball were the Moon, the wall the planet and the lamp the Sun, moving the ball can simulate the different instances of eclipses of the Sun.
Types of solar eclipse
- Total eclipse. It can be seen only from a certain area of the planet, in the center of the shadow cast by the Moon on Earth. From there, you can observe the total hiding of the luminous star.
- Partial eclipse. There is a partial concealment of the Sun and it can be seen from the twilight zone of the Earth, generated by the shadow of the Moon. You can see the luminous star partially hidden and, at the same time, appreciate part of its luminosity in the form of a half moon.
- Annular Eclipse Unlike the partial eclipse, due to the distance between the Moon and the Earth, the satellite does not generate a shadow that completely conceals the Sun but rather allows you to see a ring of light around it.
Precautions to observe a solar eclipse
You should never observe a solar eclipse directly . While it is a natural phenomenon, it is important to take precautions as the observation direct and time prolonged the sun, on a normal day or during an eclipse, can cause retinal burns and even permanent blindness. The radiations that emanate are very strong, capable of damaging the eyesight in a very short time, especially in the smallest.
There are glasses designed to see an eclipse , whose crystals are similar in characteristics to those of welding masks. Despite seeing it through special glasses, it is not recommended to do so for more than 30 seconds in a row. The sunglasses we wear every day do not protect in these cases.
A lunar eclipse occurs when the Earth interposes between the Sun and the Moon , leaving the latter in the dark, totally or partially, without receiving the light from the luminous star.
The lunar eclipse can be seen in all terrestrial regions from where the satellite is visible , while the total sun eclipse can only be seen from the area of the Earth where the moon casts its shadow. It can last from 30 minutes to an hour, unlike the solar eclipse that lasts only a few minutes.