Orbital Demonstration

Start Animation

Have a look at the picture to the left and imagine that you are holding the satellite up above the Earth.

What do you think will happen if you "let go"? Press the Start button to see.

That's right, gravity makes the satellite fall straight down to the surface.


Start Animation

This time, you are going to give the satellite a push in the direction of the red arrow.

Try it and see what happens. (Press Start)

Although the satellite still crashes into the Earth, it has moved around the surface a bit, rather than falling straight down. If you pushed it harder when you let go, it would get even further around before it crashed.


Start Animation

Let us try giving the satellite a really big push (shown by the big red arrow).

Can you guess what is going to happen here? (Press Start)

Although the satellite is still falling because of gravity, the big push that you gave it means that it cannot get any closer to the surface. In fact, it will keep going on for ever! In other words, it is in orbit.


[This demonstration uses JavaScript]