# An Activity to Illustrate the Flight Path Trajectory to the Moon

### Learning About the Flight Path Trajectory to the Moon

In order to send a spacecraft up to the moon one does not actually send it towards the moon.  If one did, said spacecraft would very definitely miss the moon altogether and be lost at space forever.  Instead, the Flight Path Trajectory to the Moon needs to take into account the fact that both the moon and the earth are in constant movement.

It takes approximately three days to reach the moon.  The spacecraft, therefore, needs to be set on a flight path trajectory towards the expected position of the moon in three days time:

Source

This is quite a tricky concept to teach a seven year old, so I attempted to make it a little more visual.

### Illustrating the Flight Trajectory to the Moon

I created a simple activity which illustrated the need to pre-plan the flight trajectory to the moon to my girls.  You need a long ruler, some string, some books, an attachable weight of some sort (I used a calculator) and some small scrunched up pieces of paper:

The string needs to be attached to one end of the ruler.  The long end of the string then needs to be tied to the weight.  Place one edge of the ruler on the edge of a table (or in my case the mantle piece).  Ensure most of the ruler is jutting out.  Weigh the ruler down using books.  The weight at the end of the string should be able to freely swing.  I made a little diagram on Publisher (I so enjoy using Publisher) to show what we did:

One of the girls swung the weight, pendulum style, whilst the other tried to hit it with their paper ball:

The girls learnt very quickly that they needed to throw the ball ahead of the calculator to have any chance at all of hitting it.

For the rest of my posts covering the Astronomy Unit click on the image below: