The common expression ‘once in a blue moon’ might become a reality for you as tonight, you will be able to catch a glimpse of a rare celestial event – the super blue moon.

According to Nasa, a blue moon is when we see the full moon twice in a single month. The moon’s cycle is 29.5 days, so shorter than the average length of a calendar month.

Don’t take the name too literally though. The moon will not be blue. However, on rare occasions, tiny particles in the air, typically of smoke or dust, can scatter away red wavelengths of light, causing the moon to appear blue.

This blue moon will be a supermoon, meaning the moon is closer to earth than is normal.

And it is the third of four supermoons in a row and this one will be the biggest, and closest full supermoon of 2023.

This coincides with planet Saturn, that can be seen in the sky near to the moon, also in her planetary position closest to the earth for 2023.

The next moon of its kind won’t be seen until January 2037, according to Nasa.

Livestream

Nasa explained the super blue moon is set to appear today and the moon will appear full until around Friday morning.

Saturn will also appear just near the moon.

The Virtual Telescope Project hosted by astronomer Gianluca Masi of Rome, Italy, will host a free livestream of the event starting at 05:30 tomorrow.

Also read: Ocean-users warned ahead of supermoon