Challenge No.3 Build your own solar system

Check out these two fun songs about the Sun – It’s important to note that the Sun is a ball of plasma (not a ball of gas!!!). So the second song is actually a correction for the first – so keep this in mind!!

In the solar system, planets can be divided into two groups: rocky planets and giant planets. The four closest planets to the Sun are the rocky planets: Mercury, Venus, Earth, and Mars. Rocky planets are small, have iron cores, and orbit close to the Sun. The gas and ice giant planets are Jupiter, Saturn, Uranus, and Neptune. They are very large, have no solid surface, and are made of mostly hydrogen and helium.

To learn more about each planet in our solar system, check out these solar system YouTube playlists:

• National Geographic: Solar System
• Crash Course Astronomy: course #9-19

Explore and experiment: Explore the planets in our solar system through either the NASA Solar System Explorer Game, or the NASA Solar System Exploration website. You can also down the NASA Eyes on the Solar System (app, advanced) to learn more. 

Additional reading: There are differences and similarities between planets. An interesting note is that you can also find greenhouse effects on other planets! Read this European Space Agency article “Greenhouse effects… also on other planets” to learn more.

Did you know there’s more than just planets in our solar system?

A long time ago the solar system was just a bunch of small rocks, dust, and ice. Some of this clumped together to become planets, but a lot of this material is left over. These left overs make up the Asteroid Belt, The Kuiper Belt, and the Oort cloud in our solar system. The Asteroid belt sits between Mars and Jupiter, and out past all the planets is the Kuiper Belt. It’s really cold out at the Kuiper belt and there’s a lot of ice there! Even farther out – 1,000 times further than the Kuiper Belt (!) – there’s the Oort Cloud, where we think most comets come from. Check out the videos below to learn about these strange places!

Gravity is the force that pulls you down. In fact, gravity always pulls you towards the middle of the earth – that is why people standing at the south pole don’t fall off!

Gravity is how astronomical objects are pulled toward each other, and why planets orbit around the sun. An orbit is formed when the planet is moving past the sun very fast while the sun pulls it inwards, resulting in the planet just going around the sun instead of colliding into it!

Experiment and explore: You can experiment with gravity using this PhET “gravity and orbits” simulatoin. In the “build your own solar system” activity below, you’ll be able to change the orbits of your planets! Check out how the mass of the sun or the orbital radius affect the way the planet moves.

Gravity is also related to how much you weigh on earth. You can explore how your weight changes on different planets on this exploratorium website.

Stars form when giant clouds of gas and dust collapse from their own gravity. A star forms at the centre, while the leftover gas and dust orbits around it. Through collisions, small pieces of solids slowly grow into larger and larger objects – eventually turning into planets. In the outer solar system, the planets grew so large that through gravity they attracted the gas to themselves, forming massive gaseous atmospheres.

When we talk about the scale of the solar system, there are two things we are referring to: size and distance.

Because the sizes of objects and distances between planets and stars are long, astronomers sometimes use AU (astronomical unit), whcih is roughly the distance from Earth to the Sun (150 million KM), or the distance light travels in a time period (such as “a light year”), to describe lengths and distances.

Experiment and explore! Scroll along on the If the moon were only 1 pixel website to explore how big the solar system is. Take note of the scale being used on this interactive website. You can also explore the scale of the Universe through this web app (flash required).

Also, can you figure out what the diameter of our solar system is in AU?

In science, it is not always possible to run experiments to learn what will happen. An example of this is when what we are trying to study is very large and complex – like astronomical objects or the Universe. In these cases, we can put together systems that works similarly to what we a trying to study – these systems are called “models.” When you are constructing your own solar system using scratch, you are building a model of the solar system – and by changing things in the model, you can learn how things might change as if you were able to experiment with the actual solar system.

If you have difficulty accessing Scratch, please ask us to see if we can help! Alternatively, you can try this no tech version of building your solar system – see if you can build a scale model (size) of our solar system using household items. We want to see some creative representation of the solar system! Similarly, we will share your creation – photo, video, and more – on the website and through social media.

You can also do what Astrophysicist Kirsten Banks did here!

The $2 Solar System (feat. Lots of running 🤣) pic.twitter.com/4wAlCajYQj

— Kirsten Banks (@AstroKirsten) June 7, 2020