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This animation shows the path of the Moon's umbral and penumbral shadows during the total solar eclipse of 1999 August 11. The Universal Time is displayed in the upper right corner as the animation runs.
The eclipse begins as the Moon's penumbral shadow touches down in the Atlantic Ocean (8:26 UT). The penumbra appears as a large greyish region that sweeps across the Earth from west to east. It is approximately 4,300 miles (6900 km) in diameter. Everyone located within the penumbra's path will see a partial eclipse of the Sun on August 11. Outside the path, no eclipse is visible.
About one hour later (9:30 UT), the Moon's dark umbral shadow appears as a tiny black dot at the center of the penumbra. The umbra is only about 69 miles (112 km) wide as it rushes across the Earth at velocities of 1500 miles per hour (2400 km/hr) or more. To see the total eclipse of the Sun, one must be located in the narrow path of umbra. Because the umbra is so small and is moving so quickly, the total eclipse lasts no more that 2 minutes 23 seconds from any location along its entire path.
From start to finish, the penumbra takes a little over five hours to sweep across the Earth. The umbra takes just over three hours to travel from the North Atlantic, through Europe and the Middle East before leaving the Earth's surface east of India in the Bay of Bengal.
This animation was generated from a program written by British astronomer Andrew Sinclair ( ATSinclair@aol.com). I gratefully acknowledge Dr. Sinclair's generosity in making this animation available to the Eclipse Home Page.
Fred Espenak and Sky and Telescope
Eclipse Predictions & Webmaster: Fred Espenak Planteary Systems Laboratory - Code 693 Email: Fred.Espenak-1@nasa.gov NASA/Goddard Space Flight Center, Greenbelt, Maryland 20771 USA
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Last revised: 1999 Jul 06 - F. Espenak