True anomaly

So imagine you're in a big circle, and you're moving around the circle like you're on a merry-go-round. You're the center of the circle, and you can see all around you.

Now, the circle is the path of a planet or asteroid or something else moving around the sun. But instead of going at a constant speed, it's going faster or slower at different times.

The true anomaly is how far away the planet is from where it would be if it was going at a constant speed. So if it's going faster than normal, it's closer to you (the center of the circle), and if it's going slower than normal, it's farther away.

Think of it like when you're spinning on a merry-go-round and you stick out your arm. Sometimes your arm is close to you and sometimes it's far away, depending on how fast you're spinning.

That's true anomaly!