The China Mail - Americas to witness rare 'Blood Moon' total lunar eclipse

The celestial event, observable with the naked eye, will have more than an hour of totality and can additionally be seen in parts of western Europe and Africa, as well as New Zealand.

A lunar eclipse occurs when the Earth goes between the Moon and the Sun, casting the Earth's shadow on the Moon.

A rare total lunar eclipse involves the Earth's umbra, the darkest part of the planet's shadow, covering the Moon.

According to NASA, this type of eclipse can also be called a "Blood Moon" due to the reddish-orange color the Moon can become during totality.

The coloration occurs due to sunlight scattering through the Earth's atmosphere before reaching the Moon's surface -- shorter wavelengths like blue and violet fail to reach the Moon, leaving only longer wavelengths such as red and orange to illuminate it.

As a result, the more items there are in the Earth's atmosphere -- such as clouds or dust -- the redder the Moon will appear during the eclipse.

"Keep a close eye on the weather forecast leading up to the eclipse," said NASA Chief Scientist Renee Weber in a statement. "That totality will last for close to an hour, so even if it's cloudy you may still be able to glimpse it if the clouds are scattered."

The timing of totality occurs simultaneously across time zones, and is expected to begin at 2:26 am Friday for those in Eastern Daylight Time and 11:26 pm Thursday in Pacific Daylight Time.

For about an hour both before and after totality, the moon will also be obscured in a partial eclipse.

U.Chen--ThChM