A rare super blue moon is rising. Here's how to watch it across Australia

A rare astronomical event will light up Australian skies this week. Here's what you need to know.

A super blue moon is expected on 31 August. Source: AAP / Dan Himbrechts

Key Points

• This week, the sky will be illuminated with a super blue moon, an extremely rare astronomical event.
• A super blue moon happens when a supermoon and blue moon coincide.
• After this week, the next super blue moon won't occur until 2037.

As August comes to an end, astronomy enthusiasts will be treated to the rare sight of a super blue moon.

As the name suggests, the phenomenon occurs when a supermoon and blue moon coincide.

Here's why the rare astronomical event occurs and how you can see it.

What is a super blue moon?

A super blue moon is a combination of two astronomical events: a supermoon and a blue moon.

A supermoon occurs when the moon is at its shortest distance from Earth and thus appears larger than it does at other stages in its orbit.

Due to the elliptical shape of the moon's orbit, the moon's distance from Earth varies.

The furthest it reaches is 405,696 kilometres. A supermoon occurs when it is 357,344 kilometres away.

While supermoons usually happen several times a year, a blue moon is much rarer, hence the saying, "once in a blue moon".

A rare lunar phenomenon will occur at the end of August. Source: Getty / Paul Kane

A blue moon is not actually blue in colour, but refers to two full moons that occur in one month, which happens once every two or three years.

According to NASA, this is because the moon's cycle is 29.5 days, just shorter than a calendar month, which means eventually the gap allows for a full moon at the beginning of the month and at the end.

The supermoon due on 31 August will be the month's second full moon, making it a super blue moon.

How to see the super blue moon

The super blue moon will technically occur on Thursday, 31 August, at 11.35am AEST, but this will not be the best time for viewing.

The best time to see it will be Wednesday evening, 30 August, at around sunset.

The super blue moon is also expected to be visible at the same time on Thursday evening.

NASA says the moon will not appear significantly larger, but will appear a bit brighter than usual.

You don't need a telescope or any special equipment to view the phenomena, but viewing it away from other light pollution will provide the best view.

According to NASA, the next super blue moons will occur in a pair, in January and March 2037.