Was the moon bigger and brighter than usual this weekend?

Video: Stunning images from the photographer James Burns showed London illuminated by a full moon

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The Independent Online

After a summer of multiple supermoons, some Londoners may have thought 2014 was an astronomer's "annus fabulous" due to another seemingly large, looming lunar display this weekend.

The photographer James Burns captured stunning scenes of London from the capital's rooftops, showing buildings such as the Gherkin, Heron Tower and Battersea Power Station in the shadow of a seemingly overly large and red-hued moon.

So, did the capital and the rest of the country see another supermoon this weekend?

A supermoon refers to the moment when the moon is in its "full moon" stage and also at its closest point to earth during its yearly orbit. With the moon being closer, it appears far bigger and far brighter, usually about 14 per cent bigger and 30 per cent brighter to people on the ground.

However, Dr Edward Bloomer, from the Royal Observatory, Greenwich, told The Independent that this weekend was no supermoon. In fact, Bloomer said, "I'm afraid that this was a fairly ordinary full moon. Just completely ordinary."

So what about the red appearance of the moon this weekend? That has an easy scientific explanation, Bloomer said, "The brightness and the slight colouring of the moon is caused by atmospheric conditions. Light from the moon (which is reflected light from the Sun) is scattered by earth's atmosphere as it comes down into our line of sight.

"The blue end of the light spectrum is scattered more, while the red end is less affected, so you begin to get this orangey-red tinge."

Bloomer explained that other atmospheric conditions also determine the colour and brightness of the moon, such as temperature, humidity and how much dust there is in the atmosphere. Furthermore, the clearness of the moon this weekend was down to the excellent viewing conditions; quite simply, there were hardly any clouds.

An optical illusion

Bloomer also said that the large appearance of the moon was simply an optical illusion.

"You have this phenomenon called the moon illusion," he exaplined. "The moon appears to be larger when it is lower on the horizon. We think this is simply an aspect of our own brains telling us it is larger when it is not.

"It is an optical affect. It is just due to our brains and eyes, for some reason were deem objects on the horizon to be larger and have more detail.

"There are lots and lots of optical illusions, this is just another one. The human eye and the human brain do a lot of processing."

Bloomer said that there is no clear explanation for why we seem to think objects on the horizon are larger, yet one idea suggests it harks back to our time as hunter-gatherers, when we used to scan for prey along the horizon.

Not that Bloomer never falls for the old trick of the moon appearing to be larger than usual.

"I once saw a full moon that was comically red and even though I knew all about it and I could rationalise its appearance, it still looked far too large and far too red.

"Your brain is definitely saying it seems to be larger than how you normally notice it."

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