License article

Bigger and brighter: why the moon was super-sized last night

If you caught a glimpse through the clouds over Melbourne and the moon looked bigger and brighter than normal last night, you weren't imagining it.

According to astronomer Geoff Wyatt, as the moon set behind the westerly horizon this morning it would have appeared 14 per cent bigger and 30 per cent brighter than the smallest full moon of the year, which will be on November 29.

The reason for the super-sized moon with its apparent extra dash of lunar luminescence is simple: distance. Last night's full moon coincided with a moment in its orbit when it passed closer to Earth.

Mr Wyatt, senior astronomer at Sydney Observatory, said the moon was currently 356,955 kilometres from Earth — a relative hop, skip and a jump.

The average distance between the moon and Earth is 384,403 kilometres, while at its furthest point, it can be more than 400,000 kilometres away.

This is because the path the moon takes to orbit the Earth is an oval shape, meaning distance between the two is constantly changing.


"This weekend the full moon occurs at its best and brightest when it is closest to the Earth," Mr Wyatt said.

The last time the moon was this close to Earth was March last year, when its orbit brought it within 356,575 kilometres.

The closest the moon will come to the Earth between now and 2020 is on November 14, 2016, when it will pass 356,509 kilometres away.

Mr Wyatt said there was no reason to fear the increased proximity of the moon would trigger earthquakes.

"We're talking a couple of hundred kilometres here and there over about 300,000 kilometres, it's insignificant," he said.

Astronomical Society of Victoria spokesman Perry Vlahos agreed the proximity would have little effect on tides or earthquakes.

"I went back and actually looked at the last 400 yers and picked out the earthquakes with the largest magnitudes on the Richter scale and not one occurred when the moon was closest to the Earth," he said.

"There won't be any undue effects on the Earth, apart from it being a wonderful sight."

Last night's full moon also coincided with the Eta Aquarids meteor shower, which is associated with Halley's Comet.

Best seen from the southern hemisphere, the meteor shower would have been washed out by the full moon - or again, covered by clouds - leaving only the brightest spots visible.