Total eclipse of the Moon

A totally eclipsed Moon

The Moon often goes a reddish colour during a total lunar eclipse, due to red wavelengths of light bending through Earth's atmosphere and reaching the lunar surface. Thursday's eclipse is likely to be quite red, due to all the volcanic dust in our atmosphere at the moment.

STARGAZERS ACROSS AUSTRALIA will be treated to a total eclipse of the Moon in the pre-dawn hours tomorrow, Thursday, June 16, 2011.

An eclipse of the Moon happens when the Moon moves into the Earth’s shadow. If the Moon goes through the middle of the shadow, it is a total lunar eclipse. If it “cuts the corner” of the shadow, we get a partial eclipse.

There are usually 3-4 lunar eclipses each year, but they’re not always visible from the same place.

For any particular spot on Earth, you might see 1 or 2 lunar eclipses each year.

This will be the best total eclipse for Aussie observers since the year 2000, as the Moon will be in the main part of the Earth’s shadow—the umbra—for around 100 minutes.

Weather permitting, everyone across Australia will be able to see it, although those on the east coast will miss the final stages of the eclipse, as the Moon will have dropped below the western horizon.

The further west you are across the country, the more you’ll see of the final stages. Those in WA will see the whole thing from start to finish.

The Moon will be in the western part of the sky (that’s the direction in which Sun sets).

As long as the weather is clear, you won’t have any difficulty spotting it.

What you’ll see

The Moon will begin to move into the darkest part of Earth’s shadow at 4:23am, Sydney time. From this point, they moon will appear to have a progressively larger “chunk” taken out of it. This, of course, is the Earth’s shadow projected onto the lunar surface.

As the hours go by, the Moon will get progressively darker until it is completely covered up at about 5:23am. Mid-eclipse will come at 6:13am.

Diagram of how a total lunar eclipse works

A total lunar eclipse occurs when the Moon moves into the Earth's shadow.

But by this time, for east coast observers, the sky will be getting brighter, with sunrise not far away. The Moon will be sinking lower and lower, down toward the western horizon and, for Sydney stargazers, the main part of the eclipse will finish just as the Moon dips below the horizon, and as the Sun rises above the eastern horizon, about 7:00am.

In fact, for most of the east coast, the Moon will set in the west roughly at the same time as the Sun rises in the east.

Eclipses happen slowly, so the best idea is to go outside every 15-20 minutes or so and see how it has changed. You don’t need a telescope or binoculars – just your own eyes are enough. And unlike solar eclipses, lunar eclipses are perfectly safe to watch.

Here’s a video of last December’s total solar eclipse. Tomorrow’s eclipse will be pretty similar:

What’s the best time to see the eclipse?

Here are the times for the capital cities around Australia, with the times listed as follows: start of the eclipse, when we can first expect to see a chunk taken out of the Moon; totality, which is when the Moon is fully covered up by the Earth’s shadow; mid-eclipse, when it is halfway through totality; and finally the end of totality.

Darwin: start, 3:53am; totality, 4:53am; mid, 5:43am, end of totality, 6:00am.

Brisbane: start, 4:23am; totality, 5:23am; mid, 6:13am, end of totality, 7:00am.

Sydney: start, 4:23am; totality, 5:23am; mid, 6:13am, end of totality, 7:00am.

Canberra: start, 4:23am; totality, 5:23am; mid, 6:13am, end of totality, 7:00am.

Melbourne: start, 4:23am; totality, 5:23am; mid, 6:13am, end of totality, 7:00am.

Hobart: start, 4:23am; totality, 5:23am; mid, 6:13am, end of totality, 7:00am.

Adelaide: start, 3:53am; totality, 4:53; mid, 5:43am, end of totality, 6:00am.

Perth: start, 2:23am; totality, 3:53; mid, 4:13am, end of totality, 5:00am.

Complicating matters is that for most places on the east coast of Australia, the Moon will have set below the western horizon before the eclipse is finished. Also, for most east coast locations, the time of “moonset” is pretty much the same as sunrise, so the Sun will be coming up in the east and the sky will be bright by the time the Moon disappears.

Nevertheless, if you get a chance, please go outside and take a look. If you have kids, get them involved too—a total lunar eclipse is a wonderful thing to see, and you never know when the weather gods might be kind enough to show you another one.

The next major eclipses for Australian stargazers will be:

Another total lunar eclipse, on December 10, 2011.

A total solar eclipse on Nov 14, 2012. This will be the last total solar eclipse visible from Australia for many a year, so lots of eclipse chasers are already making plans to witness it. Totality will be visible along a small strip of land in far north Queensland—the rest of the nation will see a partial eclipse instead.

Story by Jonathan Nally, SpaceInfo.com.au

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  1. Vickie says:

    I’m up and waiting! Hopefully the clouds stay away long enough in South Australia for me to be bale to witness it 😀 Looking forward to it!