What is the Solar Eclipse

Wilma Bane's image for:
"What is the Solar Eclipse"
Image by: 


When a Solar Eclipse occurs its because the earth,moon,and sun are in alignment and it must be during a new moon. Because the rapid motion of the moon, there is a maximum of about five hour's between the first and last time when the moon appears to touch the sun. During that time the dark inner shadow, which is called the "umbra", sweeps a narrow path across the earth that is never wider than one hundred and sixty seven mile's.

Those lucky enough to live in the path area have the opportunity to see a total solar eclipse, when the sunlight is completely blocked. Those who live in the outer area which is called "penumbral" shadow may see a partial solar eclipse. If the solar eclipse occurs when the moon is at it's closest point to the earth the apparent size is large enough to block out the sunlight completely. When the eclipse happens when the moon is at it's furthest point from the earth it's angular diameter is too small to cover the entire sun and a ring shaped eclipse occurs.

Before the eclipse becomes total, the light becomes reduced, and the thin crescent wanes until one intense region of light remains, thus producing the "diamond ring" effect. then this breaks up into a string of spots of intense light which is called "Bailey"s bead's" caused by the sunlight shining through the valley's at the edge of the moon. As the totality of the eclipse approaches the darkness falls with great suddenness, and the frosty white corona flashes into view against the darkened sky.

The solar corona is five hundred thousand times fainter than the sunlight, it flares out millions of miles around the sun in broad streamers extending several degrees. Rimming around the dark moon you will see a pinkish glow, the chromosphere. The prominences, bright pink spots extending from the chromosphere are sometimes visible.

After a few minutes the Bailey's beads and the diamond ring reappear, this time on the opposite side of the sun, the totality end's and the corona fades into the sunlight. The average length of the moons shadow is two hundred and thirty two thousand miles, where the average distance to the moon is two hundred thirty nine thousand miles.

The next total Solar Eclipse will be on July 22, 2009.

In which the moons umbral shadow will extend across India, China, and a handful of the Japanese Islands and the South Pacific Ocean. A partial eclipse will be seen in a broader path of the penumbra shadow which will include most of Eastern Asia, Indonesia, and the Pacific Ocean.

More about this author: Wilma Bane

From Around the Web