The Solar System

Our solar system is a blip in the universe, but even our solar system is enormous. Make a Solar System to scale to give a sense of the relative size of the planets and the space between them.

To learn about the planets in our solar system, and what is beyond our solar system, rockets take off from earth carrying unmanned probes.
Shoot off a baking soda and vinegar rocket and/or film canisters with Alka seltzer to show the physics of how a rocket takes off. Use molecule models to show the the chemistry of a real rocket.
Use a balloon rocket to experiment with how the weight of a rocket affects how fast it can fly, and to highlight that fuel is a significant part of the mass of a rocket.

Once a rocket takes a space probe beyond earth’s gravity, the gravity of the sun and other planets are used to alter the path and speed of the probe, to send it to a targeted planet and/or beyond the solar system. Model with the gravity assist activity.

The images that we get back from probes of the surface of planets help us understand the climate, geology and history of the planets and their moons. Craters are the dominant feature on many solid Solar System objects. Model crater formation to see what the features of craters can tell us about a planet's makeup. Model the formation of planet features formed by wind and flow of liquids and what they tell us about a planet's climate, geology and history.

Optionally talk about how the solar system was formed:
The solar system started as a cloud of gas and dust particles. Even these tiny particles have gravity and so are attracted to each other. The centre of the cloud got dense and hot enough for nuclear reactions to start (H2 fusing together), and our sun to be born.
The remaining gas and dust was slowly attracted into the planets. The closer planets, with the warmth of the sun evaporating any water, were made from metal and rock. The outer planets, far enough from the sun for ice and small molecules to stick around, formed the large gas giants.