A total lunar eclipse happens when the moon is completely in the Earth's shadow, and any light reaching the moon must first pass through the Earth's atmosphere. Instead of reflecting sunlight, the shadowed moon is bathed in a red light that bends around our atmosphere.

Why is it red?

As sunlight passes through our atmosphere it is refracted, or bent, and the green to violet part of the light spectrum is filtered out, leaving the red part of the spectrum least affected. According to astronomer Dr Michael Brown, the colour will be identical to that of a "sunset on a dusty, windy day", with the degree of brightness depending on how much cloud there is in the region, as well as the amount of dust particles in the atmosphere.

Is this the same as a 'blood moon'?

More or less. The term 'blood moon' has recently been popularised in religious prophecy to describe the four full moons of a lunar tetrad.

How often does it happen?

Lunar eclipses are relatively common, typically occurring once or twice a year. But Wednesday's lunar eclipse is special: it is part of what astronomers call a lunar eclipse tetrad - a series of four consecutive total eclipses occurring about six months apart. The first in the series happened on April 15 this year, and the final two are forecast for April 4, 2015, and September 28, 2015.  

How is it different from a solar eclipse?

During a solar eclipse, the sun is either partly or wholly obscured by the moon. Lunar eclipses are also much easier to see than solar eclipses due to the moon's proximity to the Earth - it is much easier for the Earth to block sunlight to the moon, than for the moon to block light from the sun. "To see a total solar eclipse, you really need to be in the right place at the right time," Dr Brown says. "With a lunar eclipse, as long as there are no clouds, anywhere is pretty good."

Do I need a pinhole camera?

No. Unlike a solar eclipse - which should only be viewed through special glasses or a solar filter -  a lunar eclipse is completely safe to watch with the naked eye.

Does the moon have to be full?

Yes. Dr Brown says a full moon is necessary for a lunar eclipse to occur, as the moon needs to be directly opposite the sun in the sky at the time. 

When will we see it? (times are AEDT)

People in Victoria, NSW, Tasmania and the ACT will be able to view the lunar eclipse from 8.15pm to 11.35pm on Wednesday. 

Queenslanders will be ablet to view it from 7:15pm to 10:35pm, while in South Australia the elipse will begin at 7:45pm and end at 11:05pm. 

In Western Australia, the eclipse should be visible from moonrise at 6:19pm until it ends at 8:35pm.

In Melbourne, residents in the western and northern suburbs will get the best view. But south and east-siders, don't despair: the difference is not so great that you'll miss the extraordinary sight. Although the Bureau of Meteorology is forecasting a few showers in the afternoon, they are expected to clear by dark and just in time for the lunar eclipse.

In Sydney, University of Sydney associate professor of physics, John O'Byrne, said predictions of scattered clouds Wednesday evening should not deter amateur local astronomers.