What is an eclipse and how does one occur? This is quite a common question and today it is possible to observe and understand these phenomena better as we have some amazing tools to study them.
Myths and fears
There was a time when eclipses were regarded with fear and apprehension. Even today, there are some cultures of the world where one of these amazing phenomena is considered an unholy celestial event with satanic overtones.
It was not until Galileo invented his telescope that people began to look upon these events in a new light. Galileo was able to observe and explain the movement of celestial bodies with the telescope. He studied eclipses and explained how they occurred.
An eclipse is a celestial phenomenon that occurs quite infrequently. There are two types of events. There is the solar eclipse and the lunar eclipse. The word eclipse means to cast a shadow or to block a source of light.
An eclipse occurs when the sun, the moon, and the earth are perfectly aligned in a straight line. The planes of the orbits of the earth, the moon, and the sun are all different and hence they do not align themselves very often. This explains why eclipses occur infrequently.
A lunar eclipse occurs when the shadow of the earth falls on the moon. The moon is eclipsed and hence the term lunar eclipse. However, whenever a lunar eclipse occurs, it does not obscure the moon completely every time. There are times when the shadow of the earth falls only partly on the moon. This is called a partial lunar eclipse. A lunar eclipse can occur on full moon nights only. It is safe to watch a lunar eclipse even without special glasses and protection for your eyes.
A solar eclipse takes place when the moon comes in between the earth and the sun. The moon obscures the sun temporarily and an eclipse is seen. Obviously, this occurs during the daytime only. A solar eclipse is less frequent than a lunar eclipse. This is because the moon is very close to the earth when compared to the sun. A solar eclipse can take place only on new moon days. The region of dark shadow is called the umbra and the region of light shadow is called penumbra.
Always remember to be careful of eclipses. Please avoid looking at an eclipse without supervision of a trained adult and without proper eye gear, as this can be dangerous for your vision!