What is 1 billion light-years in diameter?

A galaxy as big as 1 billion light-years in diameter is like a giant cookie that stretches from one end of your town to the other, but way, way bigger.

How Big Is a Billion?

Imagine you have a really long string. A light-year is how far light travels in one year, that’s about 5.88 trillion miles! Now think about putting 1 billion of those strings end to end. That would make a super-long line stretching from Earth to the Moon and back many, many times.

What Does It Look Like?

If you could see this giant galaxy, it would be like looking at a round pizza that covers your whole neighborhood, but instead of cheese, it's full of stars and planets, all dancing together in space. That’s how big 1 billion light-years in diameter really is!

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Examples

Imagine a ball that's as big as Earth, but stretched out to cover the whole solar system.
If you could drive at 60 mph for 1 billion years, that’s how far you’d go.
It’s like having a cookie that takes up the entire room, and there are millions of such cookies.

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Categories: Science · light-year· distance· cosmos