Look to the skies this evening and, weather permitting, you'll see something rather special happening above the UK.
On 12 August 2026, the Moon will pass between the Earth and the Sun, producing a solar eclipse. While parts of Spain, Iceland and Greenland are in the path of totality, here in the UK we'll experience a partial solar eclipse, with the exact timing and amount of the Sun covered depending on where you are.
For many locations, the most interesting part of the eclipse will occur shortly after 7pm, with maximum eclipse around 7:02pm–7:13pm depending on location.
But why can something as comparatively tiny as the Moon block something as enormous as the Sun? And, more importantly for us, can a nicotine pouch can help explain it?
It turns out that the can…can!
What Actually Is a Solar Eclipse?
A solar eclipse happens when the Moon passes between the Earth and the Sun, causing the Moon's shadow to fall across part of the Earth.
There are several different types. During a partial solar eclipse, only part of the Sun is obscured. During a total solar eclipse, the Moon completely covers the Sun's bright disc for observers standing within a relatively narrow path across the Earth.
The reason totality is possible at all is an extraordinary astronomical coincidence.
The Sun's diameter is approximately 400 times greater than the Moon's, but the Sun is also approximately 400 times farther away from us. Consequently, when viewed from Earth, the two objects appear remarkably similar in size.
Get the alignment right and our relatively tiny Moon can therefore appear large enough to cover a star approximately 1.4 million kilometres across.
Total eclipses aren't extraordinarily rare somewhere on Earth, they occur roughly every year and a half, but experiencing one from any particular place is a very rare event. NASA notes that, on average, a particular location on Earth experiences totality only around once every 375 years.
Remember the 1999 Eclipse?
For many people in Britain, today's eclipse will bring back memories of 11 August 1999.
That eclipse was particularly memorable because the path of totality actually crossed part of the UK, passing over Cornwall and parts of Devon. Millions of people elsewhere across Britain experienced a substantial partial eclipse.
The combination of enormous public interest, eclipse glasses appearing everywhere and inevitably, British weather made it one of the most memorable astronomical events in recent UK history.
Today's event isn't a repeat of 1999 for Britain: the UK is outside the path of totality this time. We will instead see the Moon obscure part of the Sun as the eclipse progresses towards sunset.
That raises an interesting question, just how enormous are the distances involved?
Let's Make the Moon the Size of a Nicotine Pouch Can
Numbers such as 384,400 kilometres and 150 million kilometres are difficult to visualise.
So let's shrink everything.
A standard nicotine pouch can is approximately 70mm in diameter. Imagine that this little round can is the Moon.
The real Moon has a diameter of around 3,475km, making it roughly 49.6 million times larger than our 70mm model.
Once we've established our nicotine-pouch Moon, we can scale everything else down alongside it.
The Moon: 70mm
That's easy. It's the can in your hand. Put it down on the ground and we've got ourselves a Moon.
The Earth: About 25cm
On approximately the same scale, the Earth would be roughly 25cm across—around the size of a small globe or large football.
Already, the relationship becomes easier to appreciate but the Moon isn't sitting right next to the Earth, though.
Our 25cm Earth would need to be approximately 7.7 metres away from our 70mm nicotine pouch can or roughly the length of a bus.
Stand next to the Earth and look towards that tiny can eight metres away. That's our scaled-down Earth-Moon system.
But now we need the Sun and this is where things get ridiculous.
Our Model Sun Would Be Around 28 Metres Across
If our Moon is only 70mm across, our scaled Sun needs to have a diameter of approximately 28 metres which is roughly the height of a nine-storey building.
So imagine replacing your little 70mm nicotine pouch can with an enormous sphere towering above the surrounding houses.
Except we can't put it next to our model Earth. To preserve the roughly 400-to-one relationship that makes total eclipses possible, our enormous model Sun would need to be around 3 kilometres away.
So picture the arrangement; you've got a 25cm Earth, about 7.7 metres away, there's a 70mm nicotine pouch can representing the Moon and roughly 3km away, there's an enormous 28-metre-wide Sun.
Stand in exactly the right position behind our little 70mm Moon, though, and that tiny object can obscure the enormous sphere in the distance.
That's essentially what you're watching during an eclipse.
NASA describes this relationship as a "cosmic coincidence": the Sun is about 400 times wider than the Moon but also about 400 times farther away, making the two appear almost exactly the same size in our sky.
Even more remarkably, this situation won't last forever. The Moon is gradually moving away from the Earth by around 3.8cm per year, so hundreds of millions of years from now it will appear too small to completely cover the Sun.
No Eclipse Glasses? Your Old Pouch Can Might Actually Be Useful
Eclipse glasses have understandably been in high demand, but you must never look directly at today's partial eclipse without suitable solar-viewing protection.
Regular sunglasses aren't enough, either.
NASA warns that partial eclipses should only be viewed directly using proper solar viewers. Looking directly at the Sun can cause serious and permanent eye damage.
If you don't have eclipse glasses, however, there's another way to see what's happening: projection.
NASA recommends pinhole projectors as a simple method of indirectly viewing a partial eclipse. Instead of looking towards the Sun, a tiny hole projects an image of the Sun onto another surface that you look at instead.
And an empty nicotine pouch can gives us the beginnings of a suitably on-brand DIY version.
Take a completely empty can and remove the removable used-pouch compartment from the top if your can has one. Then carefully make a very small, clean hole in the centre of the lid with a pin.
With the Sun behind you, allow sunlight to pass through the pinhole and project onto a flat, pale surface. Depending on your setup and the projection distance, you may be able to see a small image of the partially eclipsed Sun.
The crucial part is to never look through the pinhole at the Sun.
The hole is not a filter and does absolutely nothing to make direct viewing safe. You're looking at the projected image, with your eyes facing away from the Sun. NASA recommends projection surfaces substantially farther from the pinhole for a larger, clearer image, so projecting onto a separate white card or other pale surface is likely to work better than trying to use the shallow inside of the can itself.
It's a simple demonstration of exactly the same principle that makes pinhole cameras work and gives an empty can one last job before recycling.
A Very Big Event Explained With a Very Small Can
There's something pleasing about using an everyday 70mm object to demonstrate the extraordinary scale of an eclipse.
Hold a nicotine pouch can in your hand and imagine that it's the Moon. Now picture a football-sized Earth almost eight metres away. Finally, imagine a 28-metre-wide ball several kilometres down the road representing the Sun.
Despite that enormous difference in size, from the right viewpoint our tiny model Moon and gigantic distant Sun appear almost identical in diameter.
Today, those three real objects line up once again and although the UK won't experience totality as Cornwall did in 1999, a partial solar eclipse still gives us an opportunity to watch that remarkable piece of celestial geometry unfold.
Just remember: don't look directly at the Sun during the eclipse without proper solar-viewing glasses. If you haven't managed to get any, turn your back on the Sun, grab an empty pouch can and a pin, and try projection instead.
For once, staring into an empty nicotine pouch can might actually show you something more spectacular than your current favourite flavour.
