The phenomenon of an eclipse is as old as the universe itself. In ancient times, people did not realize that an eclipse was just a celestial phenomenon, but associated the occurrence with a bad omen or the wrath of the gods. This is no longer the case for most. We have learned the causes behind the eclipse, yet they still inspire awe and amazement.
Basically the term eclipse refers to a situation where the light of a celestial object is partially or completely blocked by another object so that a shadow appears in its place. You might compare it to a light bulb and your hand projecting its image on the wall. This seems to be quite a simple phenomenon but the grandeur of the event lies in its scale. We are not talking about petty objects or even giant structures here, but complete planets and celestial bodies. You can take a look at the sketch on the right to understand this concept.
Types of Eclipses
We will only talk about eclipses which involve the Sun, Moon and the Earth. In this context, eclipses can be divided broadly into two types - solar and lunar. In this article we’ll be focusing on solar eclipses, which can be further subdivided into various sub-categories such as total solar eclipse, partial solar and annular eclipse.
An total solar eclipse occurs when the moon is positioned between the Sun and the Earth in such a manner that it completely obscures the visibility of the Sun from the Earth even if for a brief period of few minutes. This is a very spectacular sight to observe. An annular solar eclipse is due May 20, 2012. If you miss this chance, or do not live in an area where it is visible, there are other opportunities to view eclipses.
The Total Solar Eclipse
Since the Moon is so much smaller in size than the Sun, how can it complete cover it? Although the Sun is much bigger than the Moon, it is also located very far off from the Earth as compared to the Moon. Hence the apparent size of the two happens to be the same, whenever the Moon comes at a particular position during the cosmic cycle. At that brief point of time a total eclipse is evident in a narrow range of land on the Earth which is of the order of few hundred miles. People in most parts of the world see a partial eclipse depending on their location on the planet. For the next chance to view a solar eclipse visit the NASA website fo find more details.
In the excitement of watching the event do not forget the safety aspects of viewing the total solar eclipse (or any other solar eclipse for that matter). Your eyes are very important and delicate and should be protected from radiation effects of the sun by using appropriate vision aids for watching the eclipse.