What is a Solar Eclipse? What causes a Solar Eclipse?
To start on the path toward understanding a solar eclipse we should probably know what an eclipse is, in more general terms. The word “eclipse” dates back hundreds of years. A broad definition of eclipse states that this process makes on object less prominent or less important.
As used in astronomy the term is applied to events in which one celestial object is obscured by another. For example, a solar eclipse occurs when the Moon passes between the Earth and the Sun. From our vantage point on this planet, the Moon covers all or part of the Sun. A solar eclipse happens only during the new moon phase. The Sun and the Moon are said to be “in conjunction” from our point of view.
The eclipse process generates a lot of excitement among people on our planet. These individuals travel long distances to be in a location from which an eclipse can be seen at its best. According to current records, there were significant solar eclipses in 1999, 2005 and 2006. July 11, 2010 was the date of the last total solar eclipse. Another is expected on November 13, 2012. During a total solar eclipse the sky darkens quickly. The Sun seems to disappear.
Before human beings understood a lot about the natural phenomena of our universe they were frightened by such events. The disappearance of the Sun would have been a terrifying event, equal to the end of the world. In addition, the solar eclipse was very rare, so some people may have been aware of only one in their entire lives. The Moon is in the correct position for an eclipse only twice annually. This position must combine with a new moon during that short period.
There are three types of solar eclipse. We have already mentioned the total eclipse, when the Sun is blocked from our view entirely. A partial eclipse blocks only part of the Sun from our view. During an annular eclipse we see a very small ring of light from the Sun.
Two other terms used in discussing the solar eclipse are umbra and penumbra. These are the areas of the Moon’s shadow and are keys in determining if we will see a total eclipse or a partial eclipse. It all has to do with the exact position of the Moon and Sun in relation to each other.
Lunar, not Solar
People on Earth may also experience a lunar eclipse, which occurs when the Moon passes behind the Earth. This blocks the light of the Sun, keeping the light from striking the Moon’s surface. This occurs when there is a full Moon. A total lunar eclipse will occur on December 21, 2010.
While eclipse chasers might have to travel to a specific location to get the full experience of a solar eclipse, the lunar eclipse will be visible from anywhere on the side of the Earth that is experiencing night. Lunar eclipses last for a few hours while solar eclipses are at their best for just a few minutes.