ELI5: Explain Like I'm 5

Meridian circle

Okay kiddo, imagine you are standing in a big field with your friend on a sunny day. Now, you both want to know where North, South, East, and West are.

This is where the meridian circle comes in! It's actually a big circle, like a hula hoop, with a telescope in the middle. You can rotate the circle around the telescope to look at different parts of the sky.

Now, imagine that the sun is directly overhead. This is called noon, and it's the middle of the day. If you look through the telescope on the meridian circle, you will see a line (like a ruler) inside the circle that points straight up and down. This line is called the meridian, and it shows you where North and South are.

If you follow the meridian line down, you can also see where East and West are. So, if you're standing with your back to the meridian, you will be facing East. If you're facing the meridian, you will be facing West.

It's kind of like using a compass to find your way when you're lost, but the meridian line is in the sky and helps astronomers and scientists study the stars and planets.