An eclipse takes place when one celestial body such as a moon or planet moves into the shadow of another celestial body. There are two types of eclipses on Earth: an eclipse of the moon and an eclipse of the sun, or solar eclipse.
When the moon moves between the sun and Earth it blocks the light of the sun from reaching Earth. This causes a solar eclipse, where the moon casts a shadow onto Earth. On August 21, 2017 that shadow will be cast upon Lincoln City, Oregon.
A total solar eclipse is only visible from small areas at a time on our planet. To view a total solar eclipse, you must be in the center of the moon’s shadow when it hits Earth. Day becomes night as the sky darkens. For a total eclipse to take place, the sun, moon and Earth must be in a direct line. If you are outside this path you will only see a partial eclipse. Unlike lunar eclipses, solar eclipses only last for a few minutes.
During a solar eclipse, the moon casts two shadows on Earth. The first shadow is called the umbra. This shadow gets smaller as it reaches Earth. It is the dark center of the moon’s shadow. The second shadow is called the penumbra. The penumbra gets larger as it reaches Earth. People standing in the penumbra will see a partial eclipse. People standing in the umbra will see a total eclipse.
Solar eclipses happen once every 18 months at different locations throughout the world, often times in remote locations. Viewing a total solar eclipse is a rare and special occasion.