In Pics | Six facts to know about the Beaver Blood Moon

Astronomy enthusiasts and skywatchers in general around the world were treated to the rare spectacle of a 'Beaver blood moon' on November 8 as the Earth, moon, and sun aligned to produce a total lunar eclipse for the last time until 2025. Here are some interesting facts about Beaver blood moons and lunar eclipses.

What's happening: A total lunar eclipse occurs when the Earth casts its shadow completely over a full moon, blocking the reflection of all direct sunlight from the lunar orb and dimming the colour of the moon to a reddish hue, hence the term 'blood moon.' This is only possible when the orbits of the Earth, moon and sun align so that the moon is directly behind Earth relative to the sun. Credit: Reuters Photo

Why red: The reddish appearance of the lunar surface - the moon does not entirely disappear from view - is caused by rays of sunlight around the outer edge of the eclipse shadow, or umbra, being filtered and refracted as it passes through Earth's atmosphere, bathing the moon indirectly in a dim copper glow. The degree of redness depends on atmospheric conditions that vary with levels of air pollution, dust storms, wildfire smoke and even volcanic ash. Credit: AFP Photo

How rare: Total lunar eclipses occur, on average, about once every year and a half, according to NASA. But the interval varies. Today's event will mark the second blood moon this year, following one in mid-May. The next one is not expected until March 14, 2025. Credit: AFP Photo

Where it is visible: Today's eclipse was visible across eastern Asia, Australia, the Pacific and North America. Skywatchers in Asia and Australia witnessed it with their evening moonrise, while the spectacle will play out for observers in North America in the early morning hours before the moon sets. It will be visible to the naked eye wherever skies are clear in those regions. Credit: AFP Photo

How long it lasts: The entire eclipse will unfold over a period of nearly six hours as the moon gradually edges into the Earth's paler, outer shadow, its penumbra, then enters the Earth's darker, inner shadow, or umbra, before reaching totality and eventually emerging from the other side. Credit: AFP Photo

Why Beaver Moon: Today's event coincided with the 'Beaver moon', a moniker for November's full moon adopted by the Old Farmer's Almanac supposedly from Algonquian languages once spoken by Native Americans in the New England territory. When combined with the phenomenon of a total lunar eclipse, it is widely referred to as a 'Beaver blood moon' in the United States. Credit: AFP Photo