Solar Eclipses: What They Are, When to See Them, and How to Watch Safely

A solar eclipse remains one of nature's most spectacular shows — the moment when the Moon slides between Earth and the Sun, casting a shadow across the land and turning day briefly into twilight. If you've ever witnessed one, you'll remember exactly where you were standing and how the temperature dropped as the light drained from the sky.

What actually happens during a solar eclipse

A solar eclipse occurs when the Moon passes directly between the Earth and the Sun, blocking some or all of the Sun's light from reaching us. It's a cosmic coincidence that makes eclipses possible: the Sun is about 400 times wider than the Moon, but it's also roughly 400 times further away, so from our viewpoint they appear almost exactly the same size in the sky.

There are three types. A total eclipse happens when the Moon completely covers the Sun, revealing the Sun's corona — that ethereal white halo you see in photographs. A partial eclipse means the Moon only blocks part of the Sun's disc. An annular eclipse occurs when the Moon is slightly further from Earth in its orbit, so it appears smaller and leaves a bright ring of sunlight visible around its edges.

The shadow the Moon casts on Earth is surprisingly small — typically no more than a couple of hundred miles wide — which is why total eclipses are rare events for any particular location.

When and where you can see solar eclipses in the UK

Britain doesn't get total solar eclipses often. The last one visible from mainland UK was in August 1999, when the path of totality crossed Cornwall and Devon. Many of us remember the strange half-light, the birds falling silent, and — for those lucky enough to have clear skies — those precious couple of minutes of totality.

The next total solar eclipse visible from parts of the UK won't arrive until September 2090, though northern Scotland will see one in 2053. That's the frustrating geography of eclipse paths — they're narrow and they don't wait around.

Partial eclipses are far more common. The UK sees one every few years, where the Moon takes a bite out of the Sun but doesn't cover it completely. The next significant partial eclipse visible from Britain will be in March 2025, with around a quarter of the Sun covered depending on your location.

For exact timings and visibility from your area, the Royal Astronomical Society and timeanddate.com maintain reliable eclipse calendars.

How to watch a solar eclipse safely

This is the crucial bit: never look directly at the Sun during an eclipse without proper protection. Even when most of the Sun is covered, the remaining crescent is bright enough to damage your eyes permanently. Sunglasses, smoked glass, CDs, and camera filters are not safe.

The only safe way to look directly at a partial eclipse is through eclipse glasses that meet the ISO 12312-2 safety standard. These aren't expensive — usually a few pounds — and they block out all but a tiny fraction of the Sun's light. Check them for scratches or damage before use.

Alternatively, you can watch indirectly using a pinhole projector. Poke a small hole in a piece of card, hold it up with your back to the Sun, and let the sunlight pass through onto a second piece of white card held below. You'll see a tiny projected image of the eclipsed Sun. It's how many of us watched eclipses at school.

During the brief period of totality in a total eclipse — and only during totality — it's safe to look with the naked eye. But the moment the Sun begins to reappear, eye protection must go back on.

Why eclipses mattered in the past

For most of human history, solar eclipses were terrifying events. Ancient cultures saw them as omens, dragons eating the Sun, or signs of divine anger. The ability to predict them was a source of enormous power.

Eclipses also proved scientifically valuable. The 1919 total eclipse allowed Arthur Eddington to photograph stars near the Sun and confirm Einstein's theory that gravity bends light. For a few minutes, when the Moon blocked the Sun's glare, stars appeared in positions slightly shifted from where they should be — exactly as Einstein had predicted.

Many of us remember the 1999 eclipse not just for the event itself but for the national excitement around it, the special broadcasts, the slightly daft eclipse glasses everyone wore, and the collective disappointment in places where clouds blocked the view.

Common myths about solar eclipses

Eclipses don't cause earthquakes, affect pregnancy, or poison food left uncovered. These are old superstitions with no scientific basis. The Moon's shadow passing over doesn't change anything except the amount of sunlight reaching the ground.

Animals do sometimes behave oddly during totality — birds may roost, nocturnal creatures may emerge — but this is simply a response to the sudden darkness, not to any mysterious force.

And no, you won't go blind from being outside during an eclipse. You'll only damage your eyes if you stare directly at the Sun without protection, which is equally dangerous on any sunny day.

Have you seen a solar eclipse?

If you witnessed the 1999 eclipse, or any other, we'd love to hear your memories. Where were you? What do you remember most? And if you're planning to watch the next one, share your plans below.