A total solar eclipse is expected to span all of North America from Mexico to the easternmost tip of Canada on Monday.
Although the astronomical phenomenon will be less dramatic in the UK, some parts of the country may see a partial solar eclipse.
What is a solar eclipse? Why is it special?
A solar eclipse occurs when the moon moves between the Earth and the sun, blocking some or all of the sun's rays from reaching the Earth.
This phenomenon is a cosmic event and requires that the sun, moon, and earth be in just the right position for the moon to cast a shadow on the earth.
When this happens, the moon casts two types of shadows.
One is a partial solar eclipse, which covers only part of the sun.
The other, more spectacular, is called a total solar eclipse. In this solar eclipse, the sun's disk is completely covered by the moon, except for a delicate halo of scattered light coming from the star's outer atmosphere.
A total solar eclipse occurs somewhere on Earth approximately every 18 months. We were lucky enough to witness it in the continental United States in 2017, but the next big opportunity won't be until 2045.
Where and when can you see a solar eclipse in the UK?
The moon's full shadow ends its journey across the globe in the Atlantic Ocean, about 620 miles (1,000 km) from Cornwall.
However, western parts of the UK should be able to see a partial solar eclipse just before sunset.
Very simply, if you draw a line from about Fowey in Cornwall to Berwick-upon-Tweed in Northumberland, all west of that line you'll get a view of the moon cutting into the edge of the sun as it disappears into the horizon. It may happen.
You need to be on high ground and have clear skies.
“The partial solar eclipse will occur at midnight UK time, so the sun will be low on the horizon and actually set before the spectacle is over,” said BBC Weather presenter Simon King.
How can I safely view a solar eclipse?
The old advice to never look directly at the sun still applies. You should not stare directly into the eclipse.
Experts recommend using eclipse glasses with special filters that block harmful UV rays. These glasses differ from sunglasses in that they completely block out all light except that from the sun.
If you don't have glasses, try making a hole in a piece of paper with a pin. With your back to the sun, hold the paper over your shoulder so that the sunlight shines through the small hole.
At the same time, hold another piece of paper in front of you.
It acts like a screen on which the sun's rays are projected.
What will the weather be like on Monday?
In Northern Ireland and western Scotland, the moon covers about 20% of the sun, so the weather is less than ideal.
BBC Weather said Monday will be cloudy in most areas, with rain expected in south-west Scotland and Northern Ireland.
Wales and western England will only see a small slippage of 2% to 10% of the eclipse, and the weather will be cloudy with rain.
How can I watch Total Eclipse online?
Viewers outside North America who want to watch the total solar eclipse can watch the live coverage on the BBC website. You can watch the event livestream, and our live page will be updated regularly with text and video.
Coverage will begin at 14:00 BST and continue throughout the day with live coverage from reporters stationed at eclipse gatherings across the US and Canada.
Where in the world can you see a total solar eclipse?
People who live in certain cities in North America get lost in a total solar eclipse that maps out exactly where the eclipse will be seen.
It spans an area from Mexico to Canada's easternmost island, Newfoundland.
Major cities where the total solar eclipse will be visible include Dallas, Indianapolis, Cleveland, and Buffalo, and Niagara Falls is expected to provide spectacular views of the total solar eclipse.
For Canadians, the road to perfection includes Hamilton, Montreal and Gander.
When was the last time there was a solar eclipse in the UK?
The last total solar eclipse in the UK was in 1999.
Thousands of people flocked to Cornwall. Cornwall was the only place in the UK to witness this event in its entirety.
When is the next solar eclipse in the UK?
The next partial solar eclipse visible from the UK is expected to be on March 29, 2025, when 30-40% of the sun's rays are expected to be blocked.
However, the next total solar eclipse in the UK is expected to occur on September 23, 2090, according to the Royal Observatory Greenwich.