Tonight, Australia's night-time skies will be darkened by a total lunar eclipse — the second of the year. The eclipse means that our planet's Moon will almost disappear from view, as the light it usually reflects from the Sun will be blocked by the Earth. What you will see is a blood red globe, as light bends around Earth's atmosphere on its way from Sun to Moon.
Lunar eclipse image via Shutterstock
A total lunar eclipse occurs when the Earth is perfectly aligned between the moon and the sun, with the moon hiding behind Earth in its umbra. Lunar eclipses aren't especially rare — definitely not as rare as solar eclipses — and there are four total eclipses happening in the next 16 months, in what astronomers refer to as a tetrad.
Lunar eclipses are nonetheless quite cool, and this is the second total lunar eclipse of the year, following the first on April 15th. There will be two more before the 16-month period of the tetrad ends, on April 5, 2015, as well as September 28 of that year.
The image above is from the April 15 solar eclipse, captured from Jerusalem by photographer 'ChameleonEye'. Where the last eclipse was a little bit of a let-down in Australia, since it occurred just after sunset, this one is happening at prime time — even in Australia's western states, the eclipse kicks off slightly later in the night, and lasts longer in totality before the moon is revealed once more. Here's a quick list of the times that the eclipse begins, totality begins and ends, and the eclipse overall ends around the country, courtesy of ABC News:
- NSW, ACT, Victoria, Tasmania: Eclipse begins 8:15PM. Totality begins 9:25PM. Totality ends 10:25PM. Eclipse ends 11:35PM.
- Queensland: Eclipse begins 7:15PM. Totality begins 8:25PM. Totality ends 9:25PM. Eclipse ends 10:35PM.
- South Australia: Eclipse begins 7:45PM. Totality begins 8:55PM. Totality ends 9:55PM. Eclipse ends 11:05PM.
- Northern Territory: Eclipse begins 6:45PM. Totality begins 7:55PM. Totality ends 8:55PM. Eclipse ends 10:05PM.
- Western Australia: Eclipse begins 6:19PM (moonrise). Totality begins 6:25PM. Totality ends 7:25PM. Eclipse ends 8:35PM.
Fun fact: tonight's total lunar eclipse, like the one before it, is a "blood moon" eclipse, where light from the Sun bends through the atmosphere of the Earth — what we experience as sunrises and sunsets around the planet — and shines onto the surface of the Moon. That reflection off the surface of the moon — known as its albedo — is around 0.12, so only 12 per cent of the light shining onto it from Earth's collective sunsets and sunrises during the eclipse is reflected back for us to see.
The "blood moon" is a simple enough effect in scientific terms, but this current tetrad has been picked up on by two Christian pastors, John Hagee and Mark Biltz, as a timely sign of the end times and as proof that Judgement Day is imminent, hinging on the fact that the eclipses fall on both the significant Jewish holidays of Passover and Sukkot. Rather than blindly speculate whether Blitz and Hagee are right or not, we'll point you to the experts at Earth & Sky, who say that blood moon eclipses have occurred at least eight times during both Passover and Sukkot in the last 2000 years.
And, in case you missed it, here's a quick glossary of all the terms you might have just read — so you can explain them to your friends. Courtesy of Google:
- Eclipse: "an obscuring of the light from one celestial body by the passage of another between it and the observer or between it and its source of illumination"
- Totality: "the moment or duration of total obscuration of the sun or moon during an eclipse"
- Umbra: "the fully shaded inner region of a shadow cast by an opaque object, especially the area on the earth or moon experiencing the total phase of an eclipse"
- Blood moon: "an idea popularized by Christian pastors John Hagee and Mark Biltz, which states that an ongoing tetrad which began with the April 2014 lunar eclipse is a sign of the end times"
- Albedo: "the proportion of the incident light or radiation that is reflected by a surface, typically that of a planet or moon"
- Tetrad: "a group or set of four"
- Moonrise: "the rising or time of rising of the moon above the horizon"
If you're still confused, here's NASA talking about the tetrad of total lunar eclipses occuring during 2014: