24 June – 12 July 2019
Call John on 086 8139405

Grange National School

Scratch

As of May 2019 there are three versions of Scratch available. The oldest version is Scratch 1.4, then there was Scratch 2.0 and the newest version just out this year is Scratch 3.0.

We sill be building our Solar System info graphic with Scratch 2.0 which is already installed in all of your computers but if you want to install it at home you can download it using the link below (I have also included links to the other versions of Scratch

Scratch 1.4
Scratch 2.0
Scratch 3.0 (also known as Scratch Desktop)

You can download the completed Scratch file from Session 1 here

The Solar System

There are 8 planets in our solar system.

Planet

Sized compared to Earth

Time for light to reach Earth in seconds if time was increased by 500

Distance from Sun in AU*

1 Mercury

2 Venus

3 Earth

4 Mars

5 Jupiter

6 Saturn

7 Uranus

8 Neptune

40%

100%

100%

50%

1100%

950%

400%

390%

0.6

0.2

0

0.5

4.2

8.5

18

29

0.38

0.72

0

1.5

5.2

9.5

19

30

*AU stands for astronomical units.

It takes approximately 500 seconds (8 1/3 minutes) for light to travel from the Sun to Earth.

If we were to magically speed up time by 500, then …

  • 500 minutes (8 hrs and 20 minutes) would go by in just 1 minute
  • 500 days would go by in just 1 day. So we could get through approximately 2 and a 1/2 years of school days in just 1 day, you would be finished all of primary school in 3 days.
  • it would take light just 1 second for light to travel from the Sun to Earth.

Session 2

Task 1

  • And a sprite to represent Mercury. Mercury is 40% the size of Earth.
  • Change the colour of each of the planets. To do this you can use the “bucket” tool

Here are what my planets looked like when I changed their colours.

Task 2

Change the backdrop of the stage by

  • Downloading this space backdrop to your desktop
  • Clicking on the Stage
  • Click on backdrops
  • Click on “upload backdrop from file”
  • Select the space-backdrop image you saved earlier to your desktop

When finished mine looked like this

Task 3

Add the following blocks to the Jupiter sprite (you will already have some of the blocks) and then do similar for the Mars and Mercury


Task 4

Create a second costume for each of the planets by duplicating the first costume (right click on the first costume and select duplicate)

The fill this new costume, costume2, with the colour yellow.

Task 4

We are now going to add some more blocks to demonstrate how long it would take us on planet Earth to see light from the different planets if we increased the speed of time by 500.

To do this we are going to ask the user to press a number, we will use 1 for Mercury because it is the first planet, 4 for Mars because it is the 4th planet and 5 for Jupiter because it is the 5th planet.

We will then wait the amount of time it takes for light to travel to Earth from that planet (0.62 seconds for Mercury, 0.5 seconds for Mars and 4.2 seconds Jupiter). We will then switch to costume2 for that planet (the yellow costume), wait for 1 seconds and then switch back to costume 1.

Here are the new blocks for Jupiter, you will need to do something similar for Mars and Mercury.