The scale of our solar system is awe-inspiring – it’s hard to wrap your head around just how big it really is. This is true for adults, but especially so for younger stargazers. When we watch the sunset, it’s easy to forget that the little orange ball dipping below the horizon is actually about 100 times the diameter of Earth (or if we measured it, 1.4 million kilometres wide). In fact, the volume of the sun is so enormous that you could fit about 1.3 million Earths inside it!
This solar system craft project encourages kids to create a scale model of the planets out of playdough, using an everyday object for the sun (in this case a basketball). Along the way, kids can explore fun solar system facts, discovering just how massive our sun is and how each planet compares. This hands-on project builds STEM skills including maths equations, scientific thinking and problem-solving as they work out each planet’s size and build their models.
The ball (sun) in this example was 280mm. We entered this figure into the clever tool on the Exploratorium website to get the individual diameters (the distance across the centre) of each planet, which we then created from playdough.
For ages 7+
What You’ll Need
- Kadink Modelling Clay Assorted 12 Pack
- Kadink A2 100% Recycled Butchers Paper Pad 30 sheets
- Sharpie Fine Permanent Markers Black 2 Pack
Instructions:
Step 1: Work out the diameter for each planet using the Exploratorium tool.
Step 2: Mix coloured playdough together to match the colours of the planets and mould them into shape (and learn some fun facts about each planet below).
Step 3: Measure each of your planets for accuracy and add or remove playdough as needed.
Step 4: Place the planets in their correct order next to the sun (aka basketball).
Mercury
Actual diameter: 4,866km
Scaled diameter: 0.9789mm
The first planet after the sun is Mercury and it is the smallest in our solar system. But despite its proximity to the sun, you may be surprised to learn that it’s not the hottest planet (that’s Venus) due to the fact that Mercury has almost no atmosphere, which means it cannot trap heat. Although it’s still sizzling with highs of 430°C, so it's probably best to pack your sunscreen.
SEE ALSO: STEM at Home: Explore Your Backyard With These Outdoor Activities for Kids
Venus
Actual diameter: 12,110km
Scaled diameter: 2.435mm
Venus is a rocky planet similar in size to Earth and with very hot temperatures (around 464°C). Interestingly, it also spins the other way to most planets (all except Uranus) meaning that the sun rises in the west and sets in the east. Even more fascinating is that those rotations are very slow – it takes 243 Earth days to make one rotation but only 225 Earth days to go around the sun, which means a day on Venus is longer than a year!
Earth
Actual diameter: 12,740km
Scaled diameter: 2.563mm
The third rock from the sun is the most hospitable environment in our solar system, meaning it’s the only planet known to support life, thanks to its liquid water, mild temperatures and breathable atmosphere made of nitrogen and oxygen. Throughout history, there has been speculation that there may be life on Mars or on the moons of Saturn or Jupiter, but so far nothing has been found.
Mars
Actual diameter: 6,760km
Scaled diameter: 1.36mm
Often called the ‘Red Planet’ because of its reddish appearance, Mars has the tallest volcano and the deepest canyon in the solar system. Similar to our own planet, Mars has seasons and polar ice caps, which is why scientists think it might have once supported life, although there’s no definitive evidence.
SEE ALSO: 3 Ancient Egypt Crafts For Kids
Jupiter
Actual diameter: 143,000km
Scaled diameter: 28.76mm
Jupiter is the largest planet in our solar system and is called a “gas giant” because it’s made mostly of the gases hydrogen (about 90 per cent) and helium (about 10 per cent). Also due to its enormous size it has a massive gravitational pull, which allows it to capture and hold onto many objects, including asteroids and comets. It’s also the primary reason it has 95 moons!
Saturn
Actual diameter: 116,400km
Scaled diameter: 23.42mm
The sixth planet from the sun is most famous for its distinctive rings – which can be a fun, hands-on challenge to recreate with playdough. In real life, they’re made from billions of ice and rock particles, ranging in size from tiny dust grains to large chunks. And while they’re very wide (282,000km), they’re typically only about 10m thick.
Uranus
Actual diameter: 46,940km
Scaled diameter: 9.443mm
The planet Uranus is named after the ancient Greek god of the sky, Ouranos (sometimes spelled Uranus in English). The planet itself was the first to be discovered using a telescope by William Herschel in 1781. But it remains quite intriguing to scientists due to its extreme 98-degree tilt and unusual weather, with temperatures as low as -224°C. Brrr.
Neptune
Actual diameter: 45,430km
Scaled diameter: 9.139mm
Neptune is known for its beautiful blue colour, which is caused by methane in its atmosphere. Due to the fact it’s so far from the sun and therefore has further to travel to go around the sun, the time it takes to complete a single orbit is much longer – around 165 Earth years!
Position of the Planets
The image above shows the finished solar system craft with each of the planets separated by equal intervals, but in reality the distances are all very different and many times greater than their sizes. For example, the distance between the sun and Mercury is roughly 83 times the diameter of the sun. Which means even to show that first distance accurately, our piece of paper would need to be at least 84 metres wide! This is why for this project we’re focusing on the scale of the planets, rather than the distance between them.
