Solar Eclipse

Solar Eclipse

A solar eclipse occurs when the moon's orbit takes it to a position between the Earth and the Sun. The moon's image makes it appear that a 'bite' is taken out of the sun. The moon can completely cover the sun (at least it appears so) during a total eclipse of the sun. These are very rare, and in ancient times were thought to be mystical occurrences.

About Solar Eclipse

A solar eclipse occurs when the moon's path takes it between the earth and the sun thus forming a shadow over part of the earth below. This configuration can only occur during a new moon, when the sun and moon are in conjunction as seen from the earth. In ancient times, and in some cultures today, solar eclipses are attributed mythical properties.

Total solar eclipses are very rare events for any given place on earth because totality is only seen where the moon's umbra touches the earth's surface. Because a total solar eclipse is such a spectacular natural phenomenon many people travel to remote locations in order to observe one.

There are four types of solar eclipses:
A total eclipse occurs when the sun is "completely obscured" by the moon. The intensely bright disk of the sun is replaced by the dark outline of the moon, and the much fainter corona is visible. During any one eclipse, totality is visible only from a narrow track on the surface of the earth. The next total solar eclipse will occur on November 13, 2012.

An annular eclipse occurs when the sun and moon are exactly in line, but the apparent size of the moon is smaller than that of the sun. The sun appears as a very bright ring surrounding the outline of the moon.

A hybrid eclipse is intermediate between a total and annular eclipse. At some points on the surface of the earth it is visible as a total eclipse, but at others it is annular. Hybrid eclipses are rather rare.
A partial eclipse occurs when the sun and moon are not exactly in line, and the moon only partially obscures the sun. This phenomenon can usually be seen from a large part of the earth outside of the track of an annular or total eclipse. However, some eclipses can only be seen as a partial eclipse, because the umbra never intersects the earth's surface.

Total solar eclipses are very rare events. Even though they occur somewhere on earth approximately every 18 months, it has been estimated that they recur at any given place only once every 370 years, on average. The total eclipse only lasts for a few minutes at that location, as the moon's umbra moves eastward at over 1700 km/h.

Totality can never last for more than 7 min 40 s, and is usually much shorter. During each millennium there are typically fewer than 10 total solar eclipses exceeding 7 minutes. The last time this happened was on June 30, 1973. The next eclipse of comparable duration will not occur until June 25, 2150. The longest total solar eclipse during the 8,000 year period from 3000 B.C.E. to 5000 C.E. will occur on July 16, 2186, when totality will last 7 min 29 seconds.

Never attempt to look at the sun without proper eye protection, it is extremely dangerous and can easily cause permanent damage. Astronomy stores can supply inexpensive filters and special glasses for casual observers and solar filters for amateur telescopes.

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