大象传媒

Are Saturn's rings made from a crushed moon?

Zoomed in image of Saturn with stars in the backgroundImage source, Getty Images
Image caption,

Saturn has huge rings - what do you think they're made of?

Have you ever wondered where Saturn's rings came from?

Scientists looking at them have a new idea - they think they could be made up of a former moon!

Their new theory is that Saturn actually had no rings for most of its life - until a moon came too close to its atmosphere.

They think this happened around 160 million years ago, which is only a small amount of Saturn's 4.5-billion year life!

This is all from research by Nasa's Cassini mission - a ship that was sent into space for 20 years to look at Saturn and its moons.

What are Saturn's rings made of?

Image source, Getty Images
Image caption,

If you were looking at Saturn's rings from the planet, they would appear white

Saturn's rings are made up of dust, ice and pieces of rock. Some pieces are as tiny specks, and some are as large as mountains!

They orbit around the planet in the same way our Moon orbits Earth - because of its gravitational pull.

This is the force that draws things towards the Earth's centre - and it's the reason we don't fall off the planet!

What's the new theory?

Image source, David McNew / Getty
Image caption,

It took seven years for NASA's Cassini mission to reach Saturn. You can see a model of it here

Scientists have looked at the information sent back from the Cassini mission, and think the rings could be made of a crushed up moon.

Saturn has 82 moons. Its biggest moon - Titan - is larger than the planet Mercury!

Researchers think that 150 million years ago, one moon orbited a bit too close to the planet's atmosphere, and due to the change in gravity, was pulled apart into tiny pieces.

This would explain why the rings are made of ice, rocks and dust.

They've named this former moon Chrysalis.

Why don't the other moons get crushed?

Image source, Getty Images
Image caption,

Saturn is the second-largest planet in the solar system

Whilst the moons orbit Saturn, the way they rotate means they don't get pulled in to the planet.

However, because of Saturn's strong gravitational pull, it's suggested that Chrysalis must have orbited slightly too close, and been crushed by the planet's atmosphere.

You don't need to worry about this happening with our Moon though - it's actually getting further away from Earth!

It moves about an inch further away each year.

If you cannot see the quiz, click here.