Could a Volcano Really Change the Colour of Sunsets?

In 1883, one of the largest volcanic eruptions in history blasted huge amounts of ash and tiny particles high into Earth's atmosphere.

Soon afterwards, people around the world reported spectacular red and orange sunsets.

Scientists wondered...

Could those tiny particles have changed the way sunlight travelled through the atmosphere?

What happened to the light?

Sunlight may look white, but it is actually made up of many different colours.

Blue light has a shorter wavelength, while red and orange light have longer wavelengths.

As sunlight travels through tiny particles in the atmosphere, more of the blue light is scattered away, while more of the red and orange light continues travelling towards your eyes.

That's why sunsets often appear warm shades of yellow, orange and red.

Why did your model work?

Your container became a model atmosphere.

The milk represented tiny particles floating in the air after a volcanic eruption.

By changing the amount of milk, you investigated how different numbers of particles affected the light travelling through your model.

Scientists often use models like this to investigate ideas that are too big or impossible to test directly.

Scientists Say...

Large volcanic eruptions aren't the only things that can change the colours of sunsets.

Bushfire smoke, dust storms and pollution can also add tiny particles to the atmosphere.

Scientists continue to study how these particles affect the light we see and why every sunset can look a little different.

Learning Universe

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