SOUTHERN Cross University geographer Professor Bill Boyd, from the School of Environment, Science and Engineering said the lunar triple treat is a rare and unique occurrence that would happen again until next century.

"The three separate lunar conditions will come together simultaneously - each happens on its own time cycle but this month they occur all at the same time,” prof Boyd said.

"The supermoon happens more frequently and is called 'super' because it happens when the moon is at the closest point on its orbit around the Earth, some 25,000km closer than on average and appears larger and brighter.

"The lunar eclipse, causing the red moon, occurs when the sun, the Earth and the moon are completely aligned, so that the moon travels through the Earth's shadow.

"This occurs two to four times a year, although not usually as a full eclipse and will be the first total eclipse in 150 years.”

Prof Boyd said the 'red moon', sometimes called a 'blood moon' is a result of the moon passing through the shadow of the Earth.

Instead of going completely dark, some of the sunlight entering the Earth's atmosphere, notably in the red end of the spectrum, is scattered in a way that it gently illuminates the moon.

The blue moon is a name now used to describe a second full moon in a month. The name used to be for a fourth moon in a season (which usually has three).

There are 13 lunar cycles every year, so one month must have two full moons.

Due to the overlap between lunar cycles and calendar cycles, a blue moon occurs around every 2.7 years.

"Despite many different theories as to why it is called 'blue', usually related to the fact that it is a rare occurrence, in 1883, the moon really did appear blue, thanks to the volcanic eruption of Krakatoa,” Prof Boyd said.

"So a 'blue moon' took on the meaning of 'rarely' rather than never.”

Prof Boyd said the Gold Coast and Tweed will be prime locations to view the celestial phenomenon and areas away from street or urban lighting would be best.

"The eclipse of the super red blue moon will start with a partial eclipse at 9.48pm (Qld) with the full eclipse at 10.50pm to 12.07am, and the eclipse will end around 1.10am,” he said.

"The moon will be about half way up the sky, towards the north.”

As for the impact of the event on Earth, the major natural effect will be higher than usual tides.

However Prof Body wouldn't be drawn into what affect the triple lunar event would have on people but he did point out that the word 'lunacy', after all, comes from the word 'luna'.

Lunar facts

• Supermoons occur every 14 months or so.
• Red/blood moon is a result of the moon passing through the shadow of the Earth and occurs two to four times a year.
• Full lunar eclipse - the sun, the Earth and the moon are completely aligned, so that the moon travels through the Earth's shadow - the first in 150 years.
• A blue moon occurs around every 2.7 years.