A total eclipse of the Moon will take place late tonight.

Eddie McGonagle of the Astronomical Society of Bermuda said: ?This one favours our side of the globe. We will not see another lunar eclipse until March, 2007.?

As light radiates from the Sun, he explained, the bulk of the Earth blocks some of this light, throwing a deep shadow into space.

This shadow, called the Umbra, is conical in shape and extends outwards for 800,000 miles.

Twice each year the Moon?s orbit carries it through the shadow resulting in a dimming of the Moon?s face.

The dimming effect can range from invisibility to a copper-red or orange colour depending on how the light is refracted around the Earth?s edge, skimming through the atmosphere.

?It will be interesting to see if the Mount St. Helens eruption has thrown enough dust into the atmosphere to cause a darker eclipse this time around,? said Mr. McGonagle.

The eclipse will be seen from all places on the night-side of the Earth. The last lunar eclipse, in May, favoured the Indian Ocean.

The Moon?s disc will enter the Umbra at 10.14 p.m. and will slowly move, west to east, through the shadow for more than three hours.

The total phase begins at 11.23 p.m., and lasts for one hour 22 minutes with mid-eclipse at midnight.

There is a secondary shadow known as the Penumbra which extends about a Moon-width all around the Umbra.

?Most news sources will give the times of entry and exit from the Penumbra but in reality this shadow is so faint that these times are almost academic ? except, perhaps, when the last thin sunlit crescent of the moon is about to be swallowed up by the darker Umbra,? Mr. McGonagle said.

?The whole experience can be viewed safely with the naked eye, binoculars and telescopes can be used to see finer details.?