A lunar eclipse versus a solar eclipse

A lunar eclipse versus a solar eclipse oday’s Video of the Day from the European Space Agency describes the difference between a solar and a lunar eclipse.

A solar eclipse occurs when the moon moves between our planet and the sun, where it blocks sunlight and casts its shadow over the Earth.

A lunar eclipse, on the other hand, takes place when the Earth blocks the sunlight that is usually reflected off the moon.

The most dramatic of these events is called a total lunar eclipse, when the moon is completely engulfed by Earth’s shadow and the light that reaches the moon appears “blood red” as it is filtered by our atmosphere. A lunar eclipse is similar to a solar eclipse. However in this case, the Earth gets in between the Sun and the Moon. The Earth’s shadow falls across the Moon, creating a lunar eclipse.

The reason the Moon looks red is that as the sunlight passes through the edges of the Earth’s atmosphere, its shorter wavelengths are scattered. During a solar eclipse, the Moon actually casts two shadows toward Earth. One shadow is called the umbra which becomes smaller as it reaches the Earth. This is the dark center of the Moon’s shadow. The second shadow is called the penumbra.

The total lunar eclipse that occurred on July 27th was the longest of this century.

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By Chrissy Sexton, Earth.com Staff Writer

Video Credit: European Space Agency