When is it?
First contact (when the Moon initially touches the edge of Earth's shadow) is at 9:16pm
Second contact (when the Moon is completely inside the shadow) is at 10:58pm
Third contact (when the Moon starts to emerge from the shadow) is at 11:03pm
Fourth contact (when the moon completely leaves the shadow) is at 12:45am on Sunday.

Update: for North American readers - please see the alternate article written for you guys here.

(and for Queensland residents who lack the miracle of Daylight Saving, please deduct an hour from the times above)

What is it?
A lunar eclipse occurs when the Earth is located directly on a line from the Sun to the Moon.  Of course none of these bodies is stationary, so this means that the Moon will pass through Earth's shadow (which is essentially a cone of darkness) over a period of around 3½ hours.

Of interest is that the cone is almost exactly the size of the moon at the point the Moon passes through it.  This means that the period of total eclipse is quite short.  In the case of tonight's eclipse, just 5 minutes.

If the Moon is further away, the eclipse will be longer; if it is closer there may not be any total eclipse at all as the shadow will be too small to engulf the Moon.

Why doesn't it happen every month?
Given the explanation above, you might think that it ought to happen every month, but you know it doesn't.

The reason is that everything needs to be aligned perfectly for this to happen.  And this doesn't happen very often.  It is more common for the Moon to pass above or below the Earth's shadow cone as it orbits us.

Where is the best place to view the eclipse?
ANYWHERE!

Unlike a Solar eclipse, where the Moon's shadow casts a tiny circle of darkness on the Earth's surface, the eclipse involves the entire Moon and will happen up in the sky.  If you can see the Moon, you can see the eclipse.

Credit: Fred Espenak, NASA/Goddard Space Flight Center

Of course buildings, trees and clouds may obscure the view, but nothing else.

Reports from the Bureau of Meteorology suggest that Melbourne skies will be clear tonight.  Unfortunately, it seems Sydney, Canberra and Brisbane will be rained out, while Perth, Adelaide and Hobart will have some cloud. Residents of other locations, please check with the BoM.  Note that in Perth, the Moon will rise already partially eclipsed.

In addition, take a close look at the image above.  Anyone in Asia positioned on the very narrow line labelled U3 may have the opportunity to see the fully eclipsed Moon rise at the exact same time as the Sun sets in the opposite direction (or the Moon setting as the Sun rises for North America).  Of course this may be quite hard to see as the Sun's light will tend to overwhelm the light from the Moon.

Here in Melbourne, members of the Astronomical Society of Victoria will have telescopes (and experts) set up on the Princes Bridge over the Yarra on St Kilda Rd.

Why does the Moon appear red?
When the Moon is inside the Earth's shadow cone, you might think that it would be completely invisible.  However a certain amount of light is passing at a very low angle through the Earth's atmosphere and the atmosphere is acting as a giant lens to bend this light into the shadow area.

We all know that the Sun appears reddish (as do the clouds) at sunrise and sunset.  The reason for this is that the oxygen in the sky absorbs a certain amount of blue light.  When the sun is high in the sky, the amount of air through which the light must pass is quite small, but at sunrise or sunset, the length of the air column is much greater, thus the opportunity for blue to be absorbed is also much greater.

This means that the light from the Earth, which is being bent onto the Moon will appear quite red.

When does it happen again?
There is another Lunar eclipse in late September, however it will not be visible from Australia.  There will be two partial eclipses in 2016, both visible from Australia.  However we will have to wait until January 31st 2018 for the next total Lunar eclipse visible from Australia.

There are no Solar eclipses visible from Australia in the next ten years.  A useful list of upcoming events is available here.