'Supermoon' lights up night sky

A so-called supermoon brightened the night sky Saturday, though it might not have been quite as superas some people believed.

Supermoons occur when themoon's closest approach to the Earthknown as perigeecoincides with a full moon. Themoon has an elliptical orbit withone side about 50,000 kilometres closer than the other.

The perigee and the full moon occured within a minute of each other Saturday night (at about 11:35 p.m. ET), and the moon seemedas much as14 per cent bigger and 30 per cent brighter than other full moons this year, NASAsaid.

The average distance between the Earth and the moon is about 383,000 kilometres. On May 6 it was about356,955 kilometres away.

While that news undoubtedly got the curious or romanticgazing skyward, experts said the difference would be harder to perceive than it sounds.

"Hanging high overhead with no reference points to provide a sense of scale, one full moon can seem much like any other," NASA Science says on its website.

Eric Briggs, a volunteer with the Royal Astronomical Society of Canada's Toronto Centre, said the moon was likely to be "measurably brighter, but not perceptibly brighter."

Supermoons happen about once a year on average the March 19, 2011, supermoondrew lots of attention from stargazersand photographers.

Briggs said someone with a high-quality cameramight notice the difference, but the average person would have a hard timeperceiving a change from monthto month.

NASA said the best time to lookis when the moon was near the horizon, to take advantage of the illusion that makesthe moonseem bigger. (Many people in northern temperate latitudes take note ofthe moonillusion inJune when it appears near the southern horizon.)

NASA says most major studies showno correlation between the moon and negative human behaviour. Nevertheless, some myths link full moons to increased crime and, in the case of supermoons, to natural disasters.

The supermoon does affect the world's tides, but only by a few centimetres. Briggs said that effectis more pronounced in areas such as the Bay of Fundy, but not enough for anybody to worry about.

"As far as the end of the world, not much risk of that," he said.

If anything, Briggs said, full moons keep astronomers inside because the dimmest celestial bodies are no longer visible. He's still happy for the attention the supermoon brings, though.

"Any time anyone is interested in looking at the night sky, they're probably going to see something they find fascinating," he said.