Total solar eclipse, 2024

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On 12 August, a total solar eclipse will sweep across parts of Europe and the Atlantic ocean as the moon passes between Earth and the sun, blocking out sunlight. Parts of the US and Africa, along with the entire UK and much of Europe and Canada, will see a partial solar eclipse.

Where can I see the eclipse in the UK and US?

While the total eclipse will be short and only visible in a few areas, a partial eclipse, with the moon taking a “bite” out of the sun, will last much longer across about a quarter of the entire planet. It won’t be as dramatic as a total eclipse – the corona will not become visible, and the ambient light levels and temperatures won’t drop as dramatically – but will be watchable for many more people.

In the UK and Ireland, 90 to 96 per cent of the sun will be covered by the moon. In London, the eclipse will last from 6.17 to 8.06pm, with the maximum at 7.12. The sun will be setting, so you need to be somewhere with a clear view to the west.

In most of Canada, Alaska and the northeastern US, the moon will cover less than half of the sun. Montreal will get an 18 per cent eclipse at 1.45pm and New York will get a 9 per cent eclipse at 1.54pm.

Where can I see the total eclipse?

Totality, which occurs when the moon lines up perfectly with the disc of the sun and blocks it out entirely, will begin in Russia around midday before sweeping eastward across the Arctic ocean. It will pass just south of the North Pole and make landfall in northeastern Greenland just after 4.00pm local time.

The shadow will then rush along the eastern coast of Greenland at a speed of more than 3400 kilometres per hour. The maximum length of totality will be about 2 minutes and 18 seconds, as the moon’s shadow crosses from Greenland into the Atlantic ocean. It will cross to Iceland, at which point the eclipse will become visible from more heavily inhabited areas – everywhere it will have passed so far is home only to small villages, research stations and those specifically making the journey to see the eclipse. In Reykjavík, though, totality will be visible for just over one minute at 5.48pm local time. This is the first time a total eclipse has been visible in Iceland since 1954, and the last time one will be visible there until 2196.

European Space Agency (ESA)

After skimming the western coast of Iceland, the total eclipse will make another ocean crossing and reach land again in northern Spain just before 8.30pm local time, grazing the northeast corner of Portugal and crossing the Balearic Islands off Spain’s east coast before the sun sets and the eclipse is over.

How can I watch the eclipse safely?

During a total or partial eclipse, eye protection is needed the whole time. If you don’t have eclipse glasses, you can use a pinhole camera or even natural shadows to create a projection of the sun’s shape as the moon passes in front of it. Read this article for more details of how to do that.

What happens during a total solar eclipse?

During totality, when the disc of the sun is completely concealed by the moon, temperatures on the ground rapidly drop by several degrees and daytime transforms into twilight. The stars and the outer reaches of the sun become visible. Usually, the sun’s outermost layer, the corona, is completely lost in the glare from its far brighter inner regions, but when those are blocked out, its shimmering sheets of extraordinarily hot plasma become briefly visible to the naked eye. In all other phases of the eclipse, it is crucial to wear eclipse glasses or use a solar filter while looking directly at the sun to prevent eye damage, but during totality it is safe to look at the corona.

That is precisely what many solar scientists will be doing during August’s eclipse. Total eclipses mark a valuable opportunity to observe the corona and try to unravel its many mysteries, including why it is so much hotter than the sun’s surface.