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By  Alice Philipson

A 'supermoon' will light up the night sky on Sunday as it coincides with a meteor shower in one of the most dramatic events on the astronomical calendar. 

The moon will be at its biggest and brightest for 20 years as it reaches the point in its orbit closest to Earth – known as perigee – at the same time as it becomes full. 

Two days later, the Perseid meteor shower will reach its peak – producing "fireballs as bright as Jupiter or Venus". 

Given a dark, clear sky in a normal year, it is common to see more than 100 of the meteors an hour during the second week in August. 

However, astronomers warned the lunar glare from the supermoon could make the meteor shower difficult to see. 

Dr Bill Cooke from the American space agency Nasa's Meteoroid Environment Office, said that "lunar glare wipes out the black-velvety backdrop required to see faint meteors, and sharply reduces counts". 

But all is not lost. The debris stream left by comet Swift-Tuttle, which produces the Perseids, is wide, so the shooting stars could make an appearance well before the moon becomes full. 

Supermoons occur relatively often, on average every 13 months and 18 days, and coincidentally this summer will see three in short succession. An unusually bright full supermoon was also seen on July 12, and another is due to appear on September 9. 

But the supermoon of Sunday promises to be the most dramatic since this is when the moon will be at its closest point to the Earth all year. 

In fact, perigee will occur just 26 minutes before the moon officially reaches its full phase at 6.10pm GMT (7.10pm BST) on August 10. The two phenomena will not occur so close together again until 2034 – potentially making Sunday's supermoon the biggest and brightest of the next 20 years. 

However, the difference in distance between Earth and the moon from last month’s supermoon will be no more than a few hundred miles, meaning the variation in size will be impossible to see with the naked eye. 

At perigee, the moon is around 31,000 miles closer than when it is furthest away from the Earth and will be up to 14% bigger and 30% brighter than other full moons during the year. 

Dr Robert Massey, of the Royal Astronomical Society, said skywatchers would "certainly notice the moon will be bigger in the sky compared with normal" and said the most spectacular views in the UK would be seen from Northern Scotland, where the moon would appear lowest on the horizon. 

Tony Markham, director of the Society for Popular Astronomy's meteor section, urged skywatchers keen to see the Perseids to stay optimistic. 

"The Perseids are rich in bright meteors and so many Perseids will still be seen despite the moonlit sky background," he said, writing on the SPA's website. 

"You can minimise the effect of the moonlight by observing with your back to the moon – possibly viewing the Cassiopeia/Cepheus/Ursa Minor area. 

"If possible, keep the moon hidden behind trees or a nearby building." 

He pointed out that at this time of year the moon is relatively close to the horizon, leaving much of the sky dark. 

Mr Markham also suggested looking at an area of sky 20 to 30 degrees away from the Perseid radiant – the spot near the constellation of Perseus that the meteors appear to fly out from. 

Every 133 years, comet Swift-Tuttle swings through the inner Solar System leaving behind a trail of dust. 

When the Earth passes through, the dust cloud particles hit the atmosphere at 140,000 mph and burn up in streaking flashes of light, creating the spectacle known as the Perseids. 

The best time to see the meteors is between Saturday and Wednesday, with activity peaking on Tuesday. /Telegraph