Australians probably won't see the Solstice lunar eclipse

David Heath
Sunday, 19 December 2010 20:13

Science - Space

With the first summer solstice lunar eclipse since 1378 almost upon us, much of the world will enjoy a great spectacle; but not those of us in Australia and Asia, who will see little or none of it.

My learned friend William Atkins wrote recently of the upcoming Winter (Summer for we southern hemispherites) Solstice lunar eclipse which will certainly be a magnificent sight.

So, what is a lunar eclipse?  All eclipses involve three bodies: the Sun, the Moon and the Earth.  Obviously we're standing on the Earth, so which eclipse we're looking at depends upon which of the other two bodies is eclipsed (or obscured). 

A solar eclipse occurs when the Moon passes between the Earth and the Sun - it is an oddity of nature that the Moon has approximately the same apparent size as the Sun and thus obscures it completely when the three bodies are perfectly aligned.  Clearly this will result in a very small area of the Earth's surface experiencing the eclipse.

On the other hand, a lunar eclipse occurs when the Earth obscures the light from the Sun and thus the Moon is plunged into near darkness.  We say 'near darkness' as light from the Sun will pass around the edges of the Earth and will cause some illumination of the Moon; but obviously, as the light passes through the atmosphere, it will acquire a strong reddish hue, hence the blood-red colour of the eclipsed Moon.

This eclipse will be visible for observers in North and South America and to a lesser extent Northern Europe and North Eastern Asia (mainly Japan and surrounding areas) only.  Oh, and the great emptiness of the Pacific Ocean will have a great view!

According to the official NASA event information, probably the best place to see the eclipse will be Southern California, but unlike a solar eclipse, anyone who can see the moon while it is in eclipse will have as good a view as anyone else.

Here in Australia, the moon will rise on the evening of December 21st in the very last stages of eclipse; observers may notice a reddish tinge on the upper left portion in the few minutes after it rises.  After that, the eclipse is done.

The next lunar eclipse, in the early hours of the morning of June 16th next year, will be the almost perfect opposite of this week's event with no visibility in North America and the best view in our part of the world.