Understanding Eclipses - Total Solar Eclipse
What happens during an eclipse?
What is a Solar Eclipse?
Earth's moon travels around our planet in a slightly elliptical orbit approximately every 29.5 days from the "new" moon to the next "new" moon. As it happens, a solar eclipse only happens during this "new" moon phase.
When the Earth, new moon and sun line up in a straight path, the moon will "eclipse" the sun. The physical body of the moon comes between the sun and the Earth and this will cast a shadow down to the Earth's surface much like standing in front of a light and placing your hand in between you and the light. It's not magic, but some cultures used to think it was.
A total solar eclipse happens when the moon is close to the Earth, and therefore appears larger. This makes the moon appear to "cover" the entire sun. Relatively speaking, the moon is much too small to actually block out the entire sun. It just appears to do so.
Types of EclipsesClick thumbnail to view full-size
The Different Types of Solar Eclipses
Because of the sizes and distances involved with the Earth, its moon and the huge star we call the Sun, astronomers have classified solar eclipses into different types.
If the Earth, moon and sun form a straight line, and the moon is at the point closest to the Earth (perigee), the eclipse is called a total solar eclipse. The moon appears to black out the sun and all that remains visible is the outer corona. The actual shadow from the moon is still small and only certain portions of the Earth will be covered. These types of eclipses are very rare.
Less rarely, a partial solar eclipse happens when the new moon is between a line with the sun and Earth, but is not at its full node because of its orbital plane. Basically, this means that the Earth, moon and sun do not form a perfectly straight line and the moon appears to partially cover the sun instead of totally cover it. Only those on Earth standing directly in the darkest part of the moon's shadow (the umbra) will be able to see a partial eclipse.
Another rare event, called an annular eclipse, happens when the Earth, moon and sun are in a straight line and the new moon is at apogee (furthest away from the Earth). During an annular eclipse the outer ring, or annulus, of the sun is visible because the moon appears to be too small to completely cover the sun.
Viewing an Eclipse
How to View a Solar Eclipse
Never look directly at the sun! Do not even try to look at the sun during an eclipse. The sun's rays are powerful and dangerous to the unprotected eye. The retinas are quickly damaged by ultraviolet and infrared radiation, and the damage is permanent.
Special equipment is needed to view a solar eclipse. Special dark lenses are required for telescopes and eye wear. These lenses must also be handled with care. Once they are damaged, they may not be used for viewing the sun again.
The best way to view a solar eclipse is with a trained group of solar eclipse guides. It is also possible to view a solar eclipse on television. Television stations invest quite a bit of money to record and broadcast a solar event.
The best private way to view a solar event is with a projection system. These can be simple or elaborate, but one must never look directly through the eye piece.
United States Total Solar Eclipse 8.21.2017
The next rare total solar eclipse center will pass right over Hopkinsville, Kentucky on August 21, 2017. Get your reservations in early!
Upcoming Solar Eclipses
Type of Eclipse
April 4, 2015
Asia, Australia, N. America, S. America
September 13, 2015
S. Africa, Atlantic, Indian Ocean, Antarctica
September 28, 2015
Mostly world wide
March 8/9, 2016
S&E. Asia, N&E Australia, Pacific, Indian Ocean
Have you ever seen a solar eclipse?
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