ONE of the most awe-inspiring cosmic events in the universe is set to take place on Friday and will be visible with the naked eye all across Carmarthenshire.

A partial eclipse of the Sun, when the Moon passes directly between the earth and our nearest star, will occur between 8.22am and 10.36am.

The maximum point of eclipse - the point at which the Moon is nearest to the centre of the Sun - is due to take place over the county at exactly 9.27am.

The celestial event will be the largest of its kind in 16 years.

The rare event will see Wales plunged into almost darkness as the earth, Sun and Moon slide into an unlikely alignment.

The cosmic configuration is only possible due to the unique combination of size, distance and locations of our planet, the Moon which orbits around us, and the star at the centre of our solar system.

The Sun’s distance from Earth is almost exactly 400 times the Moon’s distance while the Sun’s diameter is roughly 400 times that of the Moon.

These random, but almost perfect and identical ratios ensure that at certain times the Sun and the Moon, as seen from Earth, appear to be approximately the same size, allowing the Moon to completely obscure the Sun as its passes between it and the Earth.

Were these size and distance ratios not matched, an eclipse would not be possible.

Friday’s cosmic coming-together will only be a partial eclipse — the last time Britain saw a full solar eclipse was August 1999.

In South Wales around 87 per cent of the Sun will be blocked for about 15 minutes and more than 50 per cent for around an hour.

According to Nasa, the black-out will begin to be visible from around 8.22am, be at its most impressive around 9.27am, and fade by 10.36am as the Moon slides across the sky beyond the Sun’s diameter.

Due to the event being only a partial eclipse, the day will not go completely black, however it will become much darker and even if the event itself is obscured by clouds, it will still be noticeably darker.

Despite the Sun being partially covered, it’s light can still cause considerable and permanent damage to eyesight, even if only looked at for a few seconds, as eyes have no pain sensors, meaning we have no idea our corneas are being burnt until it is too late.

Young children are especially vulnerable.

Sunglasses will not protect eyes looking directly into the Sun and it is imperative that binoculars and telescopes are not used.

The safest way to view the eclipse is through a projection.

Place a pinhole or small opening in a card, and hold it between the Sun and a screen – a sheet of white paper works – a few feet away. An image of the Sun will appear. Projected images of the Sun’s crescent during an eclipse may even be seen on the ground in the small openings created by interlacing fingers, or in the dappled Sunlight beneath a leafy tree.

The Sun can be viewed directly only when using filters specifically designed for the purpose. Such filters have a thin layer of aluminium, chromium or silver on their surfaces. One of the most widely available filters for safe eclipse viewing is a number 14 (or darker) welder’s glass. Aluminised mylar manufactured specifically for solar observation can also be used.

Unsafe filters include colour film, some non-silver black and white film, medical x-ray films with images on them, smoked glass, photographic neutral density filters and polarizing filters. Solar filters designed to thread into eyepieces, which are often sold with inexpensive telescopes are also dangerous.

You can also buy a pair of specialist eclipse Sunglasses, which include a very dense film that removes most of the light.

Happy viewing!