A Mount Everest-sized comet could be visible to the naked eye in the coming weeks as it makes its first visit in more than 70 years.

Since early March, 12P/Pons-Brooks has been growing brighter in the night sky enabling those with a telescope to spot it.

But it is due to make its closest approach to the Sun on April 21, when, says the Royal Astronomical Society, it will be at its brightest.

For people living in the northern hemisphere, the Halley-type comet is likely to offer the best visibility between now and mid-April, estimate the experts.

“Don’t expect it to be dazzlingly bright - the kind of image you see in photographs. It’s not going to be like that,” said Dr Robert Massey, deputy executive director at the Royal Astronomical Society.

“This is something that might just be visible to the naked eye if you don’t have a Moon in the sky, if there’s no light pollution and if the weather is really clear, then you might stand a chance.”

The periodic comet is named after its discoverers Jean-Louis Pons and William Robert Brooks and only passes by Earth every 71 years – spending most of its time in the outer solar system where it is very cold.

The icy body, which is thought to have a nucleus about 34km (21 miles) in diameter, was recognised as a comet in 1812 but was seen as far back as the 14th century.

However, its ‘curious’ green colour and occasional ‘horned’ appearance – earning it the nickname ‘Devil Comet – has generated plenty of excitement and interest among astronomers today and those fascinated by the night sky.

Spotting the comet

For the best chance of catching a glimpse of Pons-Brooks, the advice to stargazers is to look west-north-west after sunset.

Apps and websites, which guide people as to where things are in the night sky, may also help suggests the Society.

The comet won’t be visible again until 2095.

Dr Massey added: “And when you see it, it’s likely to look like a sort of small, greyish fuzz, quite typical for many comets.

“But you will have the satisfaction of knowing you’ve seen this once-in-a-lifetime object.”