Total lunar eclipses occur relatively infrequently, generally visible about twice a year from somewhere on Earth. CSIRO astronomer Dr Vanessa Moss explains what a total lunar eclipse is and when to see the next one from Australia.
What is a total lunar eclipse?
A lunar eclipse only occurs during a full Moon and when the Sun, Earth and Moon are aligned. During a lunar eclipse our Earth comes between the Sun and the Moon, blocking sunlight from directly reaching the Moon and casting a shadow across its surface. The time when the Moon is completely in Earth’s shadow is called ‘totality’.
There are two main types of lunar eclipses: A total lunar eclipse occurs when the Moon passes completely into the Earth’s shadow. A partial lunar eclipse happens when only part of Earth’s shadow covers the Moon.
When can we see this total lunar eclipse in Australia?
A total lunar eclipse, on average, lasts a few hours from start to finish. The period of totality, when the Moon is entirely in the Earth’s shadow, usually lasts for about thirty minutes to an hour with some variation for each eclipse.
The phase of totality for the eclipse on 8 November will last almost 90 minutes, making it one of the longest lunar eclipses possible. The whole eclipse duration across all phases will be almost six hours.
The first stages of the eclipse, when the Moon will gradually appear to turn red, will start at 8:09pm AEDT for people on the east coast of Australia; for those in central and western Australia the eclipse will start while the Moon is below the horizon.
The whole Moon will appear to turn red – the period of totality – starting at 9.16pm AEDT.
For people in Western Australia, the Moon will rise during the eclipse so look to the east and you’ll see the total eclipse until 7.41pm AWST before the colour begins to fade.
What is a blood Moon?
The term ‘blood Moon’ is another name for a total lunar eclipse and refers to the reddish colour of the Moon while it’s in Earth’s shadow.
Why does the Moon look red during a lunar eclipse?
A full Moon is usually lit up by sunlight and as a result, you see a bright, large Moon in the sky. During a total lunar eclipse the Moon moves through the darkest part of the Earth’s shadow. The only light that can reach the Moon passes first through Earth’s atmosphere, which acts like a filter. Earth’s atmosphere scatters blue light and only lets the red and orange light reach the Moon’s surface, giving the Moon a reddish appearance during a lunar eclipse.
How often do we see lunar eclipses?
Total lunar eclipses occur relatively infrequently, generally visible about twice a year from somewhere on Earth. Partial lunar eclipses are more common than total lunar eclipses. The next total lunar eclipse visible anywhere in the world will take place in March 2025.
When will the next total lunar eclipse be visible from Australia?
After this total lunar eclipse, the next one visible from Australia will be on 8 September 2025 in the very early hours of the morning.
CSIRO astronomer Dr Vanessa Moss says:
“This is an opportunity to get your friends and family together and go outside to look up at this natural phenomenon.
“The eclipse will be visible from across Australia even in cities. For the best view, find a place that is dark and away from light pollution.”
