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Total Lunar Eclipse

There will be a total lunar eclipse during the morning of Thursday 28th October. The Moon will enter the faint penumbral shadow cast by the Earth at 1.06 am, and the partial eclipse phase will begin at 2.14 am. The total phase of the eclipse begins at 3.23 am and lasts for about 82 minutes. The Moon leaves the central umbral shadow at 5.54 am, and the penumbral shadow at 7.03 am.

A total lunar eclipse occurs when the Earth passes directly between the Sun and the Moon, causing the Earth to block direct sunlight from reaching the Moon. However, during such an eclipse, the Moon usually remains visible because some sunlight passing through the Earth's atmosphere is refracted in the direction of the Moon. The state of our atmosphere, especially the dust content, will determine the colour of our satellite and how bright it is, during totality. The Moon can take on a variety of colours ranging from copper to dark brown or even grey, depending on the amount of dust and clouds suspended in our upper atmosphere.

The Moon passes slightly above the centre of the Earth's shadow on this occasion, causing the northern part of the Moon to appear somewhat brighter than the lower part. The eclipse will be visible, providing weather conditions are favourable, throughout much of Europe, western Africa, South America and much of North America. For Northern Ireland viewers, the Moon will be at 35 degrees altitude in the southwest at mid eclipse.

It appears that changes in the Earth's atmosphere from eclipse to eclipse make it difficult to predict precisely the duration of eclipses. So, by timing when the Earth's dark shadow crosses certain lunar features, such as the centres of craters, one can obtain useful information to help compute the length of lunar eclipses.

Make the most of this eclipse, since it will be the last total lunar eclipse visible from Europe until 3rd March 2007.

FOR FURTHER INFORMATION CONTACT: John McFarland at the Armagh Observatory, College Hill, Armagh, BT61 9DG. Tel.: 028-3752-2928; FAX: 028-3752-7174; jmfarm.ac.uk

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Last Revised: 2004 October 19th
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