I made this solar system mobile for kids room.
Step 1: You will need
1 several different colors of yarn
2 different sizes of styrene form balls
3 crochet hook
scissors, craft glue, needle...
Step 2: A single crochet
Crochet 9 balls putting styrene form balls inside as Sun, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
Step 3: Connect
Connect balls in good order of planets.
Step 4: Connect
The better changing the length of the each planet's strings If you could know the exact distance of each planets from the sun.
Step 5: Increase in strength
Put glue on each joints.