This month sees the second of two lunar eclipses this year (the first eclipse was in February). This month’s eclipse is, however, only a partial eclipse. August’s eclipse details are shown below. Times are in UT. The diagram (slightly reduced in size) was created with LunarPhase Pro.

In a Total Lunar Eclipse the Full Moon passes into the shadow of the Earth and dims very considerably and changes color, but usually remains faintly visible, lit by sunlight refracted through the Earth’s atmosphere. The atmosphere scatters blue light more than red, so that most of the light that reaches the lunar surface is red in color. Observers will therefore see a Moon that may be anything from brick-colored, through orange, rust-colored, or even blood red. Sometimes it has a dark greyish hue, depending on atmospheric conditions.


Click for larger image

Since August 2008’s eclipse is only partial, a section of the Moon will remain brightly lit, as normal. This may make it harder to see the reddish colour normally associated with a total eclipse.

The eclipse begins at 18:26 UT when the Moon enters the penumbra, the lightest, outer part of the Earth’s shadow. Since this is during daylight hours, this will be a daytime partial eclipse in South America and Western Europe. Whether noticeable darkening of the Moon will be seen during the eclipse in these parts of the world, I don’t know. The effect might ne washed out by the daytime sky. The Moon will be at its darkest between 19:37 UT and 22:43 UT when the Moon is passing through the Earth’s Umbral shadow. Eclipse maximum occurs at 21:10 UT.

The eclipse will only be visible from the eastern edges of North America and Canada but the rest of the world will be able to get a clear view of it. In South America and Western Europe, the eclipse happens shortly after moonrise. In South America, the whole eclipse occurs during daylight. In Western Europe, the eclipse occurs during mid-late evening, so it happens during the transition from daylight to evening twilight. In Central Europe, the eclipse occurs during the mid-twilight hours and in Eastern Europe, Asia and Australia, the eclipse occurs during moonset during the early-mid morning hours.

The Moon will pass well to the North of the centre of the Earth’s shadow, so the Northern edge of the Moon will still be lit by sunlight, as it will be just outside the edge of the shadow.

During the eclipse the Moon lies in the constellation of Aquarius.

This eclipse should interesting because it’s a daytime eclipse (a least in South America and Western Europe, the Far East and Australia) and the whole event can be observed without optical aid, although binoculars or a wide-field telescope will also give interesting views.

Other Colors

Red isn’t the only color to look for when the Moon glides through Earth’s shadow. Observers of several recent lunar eclipses have reported a flash of turquoise.

The source of the turquoise is ozone. Earth’s ozone layer absorbs red sunlight while allowing blue rays to pass. This has the effect of turning Earth’s shadow turquoise-blue around the edges. Look for it during the first and last minutes of totality (03:00 UT and 03:51 pm UT).

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Lunar Eclipse Videos:

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Filed under: The Moon