Early risers across North America Wednesday morning will get treated to a ‘blood moon’ as Earth’s companion undergoes a total eclipse.

Lunar eclipses occur whenever the Sun, Earth, and the Moon line up so that our planet’s shadow is cast onto the lunar disk. Over the course of about an hour or so, the shadow appears to slowly creep across the the moon, taking bigger and bigger bites until the entire silvery orb has dramatically darkened.

“The most exciting part of the eclipse is totality, that is when the moon becomes fully engulfed in our planet’s shadow and we have the chance to see our moon change from its familiar bright white to a deep dark red,” explained Raminder Singh Samra, resident astronomer at the H.R. MacMillan Space Centre in Vancouver, B.C.

The sky show begins at 2:15 am Pacific Daylight Time (5:15 am EDT) when the first hints of the partial eclipse begin. By 3:25 am PDT the moon will become totally eclipsed as it enters the deepest part of Earth’s shadow, called the umbra.

While western Canada and much of the Pacific Ocean and Asia will get to see all of the eclipse, skywatchers in Eastern and Atlantic Canada will only get to enjoy the first half of the cosmic event. That’s because by the time totality begins, the moon will be setting fast in the west just as the sun is rising in the east.

“Observers in the West will have the chance to see the eclipse in its entirety whereas observers in eastern North America will see the partial phases of the eclipse, along with he start of totality, just as the moon sets in the western horizon on Wednesday morning,” Samra explained.

While the Moon does reach full phase every month, it is a rarer occurrence for it to be covered by Earth’s shadow and change colour as it will Wednesday morning.

“This does not occur every month as the orbit of the moon is tilted with respect to the Earth’s orbit so the moon does not pass through the shadow regularly,” said Samra.

“When this does occur, however, sunlight passing through the Earth’s atmosphere is scattered towards the red end of the spectrum, which then falls on the surface of the moon giving its deep red hue.”

The more the dust particles in Earth’s atmosphere at the time of the eclipse, the darker shade of red the moon can appear. Expectations are high that this may be one of those times, thanks to the recent volcanic activity in Japan and Iceland.

“This eclipse has the ability of being even deeper red due to recent volcanic eruptions, as volcanic eruptions spew ash into the upper atmosphere and some of it can stick around for quite some time so that the ash effectively scatters light making it more red than usual,” Smara said.

But with the unpredictable weather this time of year, there is a chance that you might get clouded out. But even If you happen to be stuck indoors, you can still check out the lunar disappearing act from multiple sites around the world thanks to a live online broadcast by astronomy outreach venture Slooh.

Turns out this will be the second in a series of four lunar eclipses, known as a tetrad – a cosmic rarity that won’t repeat for another 20 years.

So if you miss this lunar eclipse there will be two more next year in April and September 2015.