There are eight known planets orbiting the Sun, including Earth. Making a model is a fun introduction to the solar system and a great art project for elementary science classes. Doing this detailed example can take a few hours, although most of the process involves waiting for the paint or clay to dry.
Steps
Part 1 of 3: Making the Sun and the Gas Giants

Step 1. Find a cardboard box
The planets of the solar system model will hang from inside the box. You will need to locate nine planets in addition to the Sun inside the box, so make sure there is enough space. This box should be at least as large as a men's shoe box, which will measure approximately 40 x 25 x 15 cm (15 x 10 x 5½ inches).

Step 2. Paint the box black
Cover the inside of the box and the outer short sides with black acrylic paint. Then, set the box aside on newspaper to dry.
For a more uniform background, outline the box on black paper. Then cut out the paper rectangle and glue it to the bottom of the box

Step 3. Gather five Styrofoam spheres
If possible, find three different sized spheres. They should all fit inside the box with a little excess space, although they should not stay tight in a row. You will need the following:
- 1 large sphere for the Sun (10 cm or 4 inches in diameter maximum)
- 2 medium spheres for Jupiter and Saturn (maximum 8 cm or 3 inches)
- 2 small spheres for Uranus and Neptune (5 cm or 2 inches maximum)

Step 4. Choose the paints
Acrylic paint is the best option, as some of the other paints can dissolve styrofoam. Choose various colors of paint to paint the planets, including orange or gold, yellow, red, white, and dark blue.
If you're not sure if the paint will work on Styrofoam, look for the label that lists cleaning instructions for the brushes. If you can remove the paint with water, it means that it is water-based and safe. If you need to use a solvent, such as white spirit or turpentine, the paint will be solvent-based and may dissolve the Styrofoam

Step 5. Paint the Sun
Slide a long skewer into the larger styrofoam ball so it stays in place. Paint the entire surface with gold, yellow or orange paint to make the Sun. Place the skewer in a tall jug or insert the end into a polystyrene block and allow the sphere to dry.
- A stencil brush or other short bristle brush will help you get the paint to stick to the corners and grooves of the Styrofoam sphere. You may need to let the first coat dry and use a larger brush to paint over it to get an even color.
- If the paint doesn't stick all the way, cover the sphere with a thin layer of caulk, let it dry, and paint over it.

Step 6. Paint the large planets in the same way
The two medium spheres are the two largest planets, Jupiter and Saturn. These planets are called gas giants. The diameter of each of them is approximately ten times larger than that of the Earth. In addition, they are made up mostly of a heavy layer of gas that surrounds a rocky core. Stick skewers inside them and place them on a styrofoam block or separate jars so that the paint-soaked surfaces don't touch.
- Jupiter's clouds form bands and spiral storms. Paint this planet with red, orange, and white paint making swirl designs.
- Saturn is pale yellow (a mixture of yellow and white paint).

Step 7. Paint the ice cream giants
The last two spheres will represent Neptune and Uranus, the smallest gas giants or "ice giants." These planets, which are four times the size of Earth in diameter, have been made up of spheres of ice and heavy elements. Since that time, these materials have become a fluid core surrounded by a swirling shell of gas.
- Paint Uranus a pale blue color made by mixing blue and white paint. White clouds sometimes form over solid blue atmosphere.
- The planet Neptune is almost the same color as Uranus, although it looks a bit darker because it is further away and receives less light. Paint it blue.

Step 8. Add the rings of Saturn
Find a glass vase with an opening the same size as the sphere you used to make Saturn. Then place it face down on gold or yellow construction paper and outline its outline with a pencil. To make a ring shape, place a larger glass upside down on a pencil circle and outline its outline. Cut out the ring, glue it around Saturn, and let it dry.
To cut the ring, start by cutting the largest circle. Then carefully fold it in half without creasing it and cut around the smallest circle
Part 2 of 3: Making the Rocky Planets

Step 1. Make five rocky planets out of clay
You can use polymer clay, air-drying clay, or a polymer clay substitute. Shape five small spheres (no more than 1 inch or 3 cm in diameter) using various colors of clay.
- The planet Mercury is a caramel gray rock with no cloud cover. However, instead of making it that color, you can use red or gold clay to create a more beautiful model.
- Make the Earth out of blue clay for now.
- Make Venus out of pale yellow clay.
- Technically, Pluto is not a planet (it is too small), but you can include it in the mockup anyway. Make it out of light brown clay. You can also mix it with a little charcoal to mimic its stained surface.

Step 2. Drill a hole through each clay sphere
Use a large needle to pierce the center of each rocky planet. Later, you will pass a thread through this hole to hang the planets inside the box.
Drill the hole through Saturn at an angle, so the rings are tilted when the planet hangs from the box. This will make the model look better and you will have more space to arrange the planets

Step 3. Let the clay dry
Follow the drying instructions that come on the clay packaging. Clay that is air-dried will dry on its own, while other types of polymer clay require you to bake them at low heat to harden.
In the case of light colored clay, it is recommended that you put it in the oven at approximately 5ºC (10ºF) lower than the recommended instructions. This type of clay can take twice as long to bake, although the risk of breaking it is lower

Step 4. Paint the land surface of the Earth
Once the clay on Earth hardens, paint the continents with green acrylic paint.
Part 3 of 3: Assembling the mockup

Step 1. Paint the stars
Once the black paint on the box has dried, use a white paint pen or small paintbrush to paint white dots on the inside of the box.

Step 2. Insert threads into the polystyrene spheres
Once the sun dries, push a skewer completely through the sphere, then remove it. Tape a clear bead string to the end of the skewer with tape and push it through the same hole. Repeat this procedure for each Styrofoam sphere.
Any length of bead string is long enough to hang a planet from the “ceiling” of the box when it is on its side. It is enough that you use 5 to 8 inches (13 to 15 cm) of thread

Step 3. Glue the thread
Hold the end of the string and remove the skewer. Knot the beading string two or three times, and then attach the knot to the Styrofoam ball using a bead of glue from a hot glue gun.

Step 4. Thread yarn through the clay planets
Once the clay planets have dried, thread the clear string through the holes you made earlier. Then, hold the string together with a hot glue gun, just like you did with the larger planets.

Step 5. Arrange the planets in the model
Lay the box on its side and attach the strings to the ceiling. Position the planets in a staggered fashion at different heights (top or bottom) and depths (front and back) so they can all fit inside the box. The spheres must be in the following order:
- Sun
- Mercury
- Venus
- Land
- Mars
- Jupiter
- Saturn
- Uranus
- Neptune
- Pluto

Step 6. Hang the planets from inside the box
Once you've found an order that looks good and fits the box, make marks on it at the ten points where you will hang the Sun and planets. Cut through the box at these points with a sharp knife and thread the string through each hole from which the planets will hang. Tape the thread together with strong tape and cut off the excess.

Step 7. Cover the top of the box with black paper
Outline the side of the box on black paper and cut out a rectangle. Then stick it over the top of the box to hide the tape. At that time, the solar system mockup will be ready for display.
