The Moon will turn red on Saturday night while moving through Earth's shadow in a total lunar eclipse.

The eclipse will be visible, if the sky is clear, from most locations on Earth.

The Moon will be completely covered during the most dramatic phase, which will last a little more than an hour, from 2244 to 2357 GMT (Greenwich mean time or Britain's time).

The Moon's environment will grow dark while the Sun is shadowed by the Earth; but our planet would still appear from the Moon as surrounded by a strange red glow, as the sunlight is refracted through the Earth's atmosphere.

In fact, you would see the combined shine of all the world's sunrises and sunsets.

That's why the Moon does not appear black but reddish orange during a total lunar eclipse, even if the glow of the eclipsed Moon can vary a lot from eclipse to eclipse, depending on the current levels of dust and clouds, factors than can refract sunlight in Earth's atmosphere.

The most complete eclipse, with the Moon totally covered by the Earth's shadow, can be watched from all of Europe, Africa, Asia westward of central China, central and eastern North America and all of South America.

From most other places, the eclipse will be partial and non-visible in the range of the Pacific Ocean from northwestern Canada to eastern Australia.

The eclipse will start at 2018 GMT and will be seen after 2130.

The most complete part of the eclipse lasts from 2244 to 2357 GMT, when the Moon is located entirely in the deepest part of the Earth's shadow.

By 0111 GMT on Sunday, the Moon will go out of the Earth's shadow, but will still be slightly shaded until 0223 GMT.

Lunar eclipses are a much more common phenomenon than solar eclipses, as the Earth and its shadow are larger than the Moon and its shadow.

In some years, even three lunar eclipses can occur.

The last total lunar eclipse occurred on 28 October 2004 and the next will take place on 28 August 2007.

Watching a lunar eclipse safely requires no special glasses, compared to an eclipse of the sun, which does.