Cosmic distance ladder

The cosmic distance ladder is like a giant step ladder that helps us measure very far distances in space. We can measure distances of billions of light-years! How do we figure out these huge distances? Well, we use several different tools called "rungs" that are like steps on a ladder.
Each rung uses a different tool to help us measure the distances. The first rung uses something called parallax. We measure the parallax of a star, which is like the way it looks like it's moving when you look at it from different places. This can tell us how far away it is.
The second rung uses the brightness of stars. By looking at how bright the stars appear from Earth, we can measure their distances.
The third rung uses supernovae, which are exploding stars. Since we know how bright supernovae should appear, we can measure their distances by comparing how bright they look from Earth.
The fourth rung uses something called the redshift. When light travels very long distances in space, it gets stretched out and turns more red. By measuring this redshift, we can tell how far away galaxies are.
The fifth and final rung of the cosmic distance ladder uses something called the cosmic microwave background radiation. We use this to measure the distances to the very farthest away galaxies!

So you can think of it like a huge step ladder that stars and galaxies are on. By using these different "rungs" we can measure even the furthest distances in space!