Lunar eclipses

Lunar eclipse

Lunar eclipse; photo © Geoffrey Wyatt

Total lunar eclipse 15 April 2014

There was a total eclipse of the Moon on Tuesday 15 April 2014. For those of us in Sydney, it was disappointing because it was cloudy throughout, so we didn’t see the eclipse.

However there were plenty of programs available to visitors to Sydney Observatory in the 3D space theatre, Sydney Planetarium and in programs led by enthusiastic astronomy guides – so our visitors were still very happy to have been part of the Sydney Observatory experience.

There was no eclipse to be seen in our live video stream. Maybe next time….

Lunar eclipse 28 August 2007, photos by Geoffrey Wyatt

Lunar eclipse 28 August 2007, photos and animation by Geoffrey Wyatt

Other video of the eclipse

The following provided a Northern Hemisphere perspective of the lunar eclipse. You may want to check these websites for other eclipses and astronomical events:
slooh
ustream
NASA
Galactic Connection
Griffith Observatory

Upcoming total lunar eclipses

On average there is an eclipse of the Moon every eight months, with a little under half of these total. The actual number of lunar eclipses in a year can range from none to a maximum of three. A total eclipse of the Moon is visible from Australia on average every 2.8 years.

There are more total eclipses over the next period than usual. In Australia, total lunar eclipses will occur on 15 April 2014, 8 October 2014 and 4 April 2015. In parts of the Northern Hemisphere there will also be a total lunar eclipse on 27 September 2015.

Why the Moon is red during a total eclipse

The Moon will appear red during totality because red light from the Sun is bent by the Earth’s atmosphere onto the Moon. The light is red as other colours such as blue are scattered in all directions leaving red, just as at sunset. Another way of putting it is that seen from the Moon the Earth is dark, but surrounded by an atmosphere lit up by either by sunset or dawn. Whether the Moon will go red and how dark a red depends on atmospheric conditions at the time of the eclipse. This post about the 2007 total lunar eclipse will give you some idea of what we can hope to see on the night.

It is safe to look at a lunar eclipse and fun to photograph it.

How do eclipses occur?
(Dr Nick Lomb, Sydney Observatory’s consultant astronomer and curator, provided the following helpful explanation in his post about the partial lunar eclipse in 2010.)
Eclipses of the Moon occur when the Moon moves into the shadow of the Earth. When the Moon is fully immersed in the dark part of the shadow we see a total eclipse of the Moon. At such times the eclipsed Moon usually takes on a dark reddish colour from the light bent or refracted onto the Moon by the Earth’s atmosphere. When the Moon is only partially immersed in the dark part of the shadow we have a partial eclipse.

Eclipse basics

How eclipses of both the Sun and Moon occur. Sketch Nick Lomb

An eclipse of the Moon can only happen at full Moon phase. It does not happen every month as the path the Moon takes around the Earth is tilted by about 5° to the path the Earth takes around the Sun. Hence at full Moon the Earth’s shadow usually falls below or above the Moon.

What is the history of Moon eclipses?
Eclipses of the Moon first provided proof that the Earth is a globe as the edge of the Earth’s shadow moving across the Moon is always part of a circle. This was noticed by the Greek philosopher Aristotle who lived in the fourth century before our era.

According to ancient Chinese legend an eclipse of the Moon occurs when a dragon begins eating the Moon. Hence the tradition in China during eclipses was to make as much noise as possible by banging on drums and pots to scare away the dragon. This technique has so far succeeded on each occasion.

More on astronomy and eclipses from Sydney Observatory

April 2014 is a month of eclipses. On Tuesday 29 April there will be a partial eclipse of the Sun seen throughout Australia – you can book here to experience the solar eclipse at Sydney Observatory.

Thanks to Dr Nick Lomb for information in his annual book, the Australasian sky guide and in the April 2014 monthly sky guide podcast which provided information for this post. Thanks to Nick also for his contributions to this post.

Just type ‘lunar eclipse’ into the search field of our blog to find out more about this phenomenon.

Check out our free monthly sky guides including podcast, sky map and transcription, giving you a guide to highlights in the night sky for each month of the year.

Check out also our free Moon phase calendar.

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