Mean motion

Okay, kiddo, so let's talk about mean motion! Imagine you're playing with a toy car that moves around in circles. The mean motion is like the average speed that the car moves around in circles.

Now, let's imagine that the toy car is actually a planet moving around the sun. The mean motion is the average speed that the planet moves in its orbit around the sun. It's like taking all the days that the planet takes to complete one orbit and averaging them together to get a typical value.

But wait - there's something called Kepler's Laws that tells us that the planet doesn't move at the same speed all the time! Sometimes it moves faster when it's closer to the sun, and sometimes it moves slower when it's farther away. So how can we talk about a "mean" motion if the planet is always changing speed?

Well, scientists do some fancy math and figure out what the average speed of the planet would be if it moved uniformly around the sun, in other words if it moved at the same speed all the time. This is the mean motion! It's not exactly the speed that the planet is actually moving at any given moment, but it's a useful value that helps us understand how the planet moves over time.

And that, young one, is what we mean by "mean motion"!