A supermoon phenomenon occurs when a full moon, on its oval-shaped orbit, is at its closest to us, known as perigee, which is about 356,000 kilometres as measured from the centre of the Earth to the centre of the moon.

It takes place when the moon’s orbit brings it to the closest point to Earth while at the same time being bathed in sunlight, giving the moon its bright appearance.

During such an event the moon looks to be about 14 per cent bigger and about 30 per cent brighter compared with when it’s at the farthest point in its elliptical orbit around Earth, known as apogee.

Australians will be able to see the supermoon in the early hours of February 20, with the absolute “peak time” being at about 2:53am AEST for those on the east coast, according to the lunar calendar.

But the good news is you you’re better off looking at it just after sunset, says Dr Brad Tucker from the ANU Research School of Astronomy and Astrophysics.

“The peak fullness is at 2.53am, but really, when people want to see the bright full moon is when it’s rising,” he said. “The full moon always rises at sunset.”

“You don’t have to wait around or look at the time. Just remember roughly around sunset go and look at the moon. That’s when you get to see it coming on the horizon and the visual effects of it appearing to be bigger look the best.”

Although closer to the Earth, tonight’s supermoon will not be as colourful as last month’s super blood moon eclipse that turned the moon a stunning shade of orange.

While there will be another supermoon in March, this week’s will technically be the closest and therefore the biggest of the year.

Given the moon orbits the Earth about once every 28 days, there is usually 12 full moons a year (sometimes 13), and there is always one or two that happen to be at the closest point to the Earth in its orbit.

However despite the supermoon’s colloquial name, Dr Tucker says don’t let your expectations get too high.

“To the general unaided eye, you won’t notice it hugely or dramatically bigger,” he said.