Only Lunar Eclipse of 2010 Takes Place Tonight

Dec. 20, 2010— -- For astronomy fans, Christmas comes early this week.

Barring cloudy weather, astronomy enthusiasts and sky gazers across North America will be treated to the only lunar eclipse of the year tonight.

The eclipse will be visible Monday night on the West Coast and during the early hours Tuesday on the East Coast.

If the sky is clear, experts say the show might be extra spectacular, as the moon will have a reddish glow.

A lunar eclipse takes place when the sun, Earth and moon are all perfectly aligned with the Earth in the middle. When the moon passes behind the Earth, the sun's rays are blocked from striking the moon. This can only occur when the moon is full.

As the moon moves deeper into Earth's shadow, indirect sunlight passes through Earth's atmosphere, casting an orange and red hue over the moon.

Unlike a solar eclipse, which can only be seen for a few moments from any specific spot, a lunar eclipse can be viewed for several hours. It is also safe to view a lunar eclipse without special glasses or equipment.