Eclipses for Kids: What Happens When the Moon Hides the Sun?
Solar and lunar eclipses explained for kids: why the moon can cover the sun, why it turns red during a lunar eclipse, why it doesn't happen every month, how to watch safely and when the next eclipse comes to your town.
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What is an eclipse?
An eclipse is a giant game of shadows. The sun, the Earth and the moon line up in a row, and one of them casts its shadow onto another.
When the moon moves in front of the sun, its shadow falls on the Earth: that's a solar eclipse. When the Earth stands between the sun and the moon, the moon slips into the Earth's shadow: that's a lunar eclipse.
The eclipse lab
Press play and watch the moon circle the Earth. Every time it passes between the sun and the Earth, it is new moon – but is it also an eclipse?
Lunar eclipse! The moon moves into the Earth's shadow and turns red.
New moon – but the moon passes above or below the sun. No eclipse this time.
Full moon – but the moon slips past the Earth's shadow. No eclipse this time.
The moon's path is tipped a little – by about 5 degrees. In most months, the moon passes just above or below the sun. Only about every six months does everything line up exactly: that's eclipse season.
On a flat path there would be a solar eclipse at every new moon and a lunar eclipse at every full moon – twelve of each per year! That's not what happens, so the real path must be tilted.
The solar eclipse: the moon covers the sun
The sun is about 400 times as wide as the moon – but it is also about 400 times as far away. That's why both look almost exactly the same size in the sky, and the moon can cover the sun perfectly.
Only where the moon's dark shadow touches the Earth does the sun disappear completely: a total solar eclipse. The shadow is at most about 170 miles wide, so the eclipse is total only along a narrow strip. All around it, people see a partial eclipse: the sun looks like a cookie with a bite taken out.
Total eclipse: The moon covers the whole sun. For a few minutes it gets as dark as dusk, the brightest stars come out, and the sun's silvery glow, the corona, appears around the black moon.
Ring of fire: Sometimes the moon is a little farther from the Earth and looks slightly smaller. Then it can't cover the whole sun, and a glowing ring is left around it. Astronomers call it an annular eclipse.
Partial eclipse: The moon covers only part of the sun, which looks like a cookie with a bite taken out. From most places, this is the kind of solar eclipse you get to see.
What happens during a total eclipse?
In the middle of the day, it gets as dark as dusk within a few seconds.
It suddenly gets cooler, often by several degrees, and a light breeze can start.
Birds stop singing and fly to their nests, and bees stop buzzing and head home.
The brightest stars and planets appear in the dark sky around the sun.
Around the black moon, the sun's glowing outer layer – the corona – shines like a silvery crown.
The lunar eclipse: why the moon turns red
During a lunar eclipse, the full moon moves into the Earth's shadow. It doesn't disappear – it glows copper-red. Why? A little sunlight still reaches it by passing through the Earth's air, which bends the light into the shadow. On the way, the blue gets scattered away, just like at sunset.
So during a lunar eclipse, the moon is lit by all the sunrises and sunsets on Earth at the same time! Unlike a solar eclipse, you can watch it without any protection, and everyone on the night side of the Earth can see it.
Watch a solar eclipse safely
Never look at the sun! Not even when most of it is covered. Its light can damage your eyes forever, and it doesn't even hurt while it happens. Sunglasses – even very dark ones – do not protect you.
Eclipse glasses: Special eclipse glasses with a safety filter (marked ISO 12312-2) let you look at the sun safely. Check them before using them: if they are scratched or have holes, throw them away.
Pinhole projector: Poke a small hole into a piece of cardboard and let the sun shine through it onto a sheet of paper. You'll see a tiny picture of the sun – and during an eclipse, a little crescent. A kitchen colander works too: it makes dozens of little suns!
Leaf crescents: Look at the shadow of a tree during a partial eclipse: the gaps between the leaves act like pinholes, and the ground is covered with hundreds of little crescent suns.
When is the next eclipse where you live?
Not every eclipse can be seen from everywhere. Here are the next ones you can watch from your town.
Partial: the Earth's shadow takes a bite out of the moon.
Dragons, wolves and a battle
A dragon eats the sun: In ancient China, people believed a hungry dragon was eating the sun. They banged drums and pots to scare it away – and it always worked!
Wolves in the sky: The Vikings told stories of two wolves, Sköll and Hati, chasing the sun and the moon across the sky. When a wolf caught up with its prey, there was an eclipse.
A battle that stopped: In 585 BC, a solar eclipse darkened the sky during a battle between two peoples in what is now Turkey. The soldiers were so frightened that they stopped fighting and made peace.
Questions about eclipses
How often is there a solar eclipse? Somewhere on Earth, two to five times a year. But a total eclipse comes back to the same place only about once every 375 years on average – that's why many people travel far to see one.
How long does a total solar eclipse last? Only a few minutes – never more than about seven and a half. The total eclipse of August 2, 2027 will last up to 6 minutes and 23 seconds in Egypt, the longest seen from land for many decades.
Is it safe to look at a lunar eclipse? Yes! A lunar eclipse is completely safe to watch – with your bare eyes, with binoculars or with a telescope. All you need is a clear sky and a view of the moon.
Why is a solar eclipse always at new moon and a lunar eclipse always at full moon? For a solar eclipse, the moon must stand between the sun and the Earth – and that's where it is at new moon. For a lunar eclipse, it must be behind the Earth, opposite the sun – and that's full moon.
Do animals notice an eclipse? Yes. During a total solar eclipse, birds often go quiet and some fly to their nests, bees stop buzzing, and some animals get ready for the night – only to wake up again a few minutes later.