We had a lot of flexibility for this lesson, but before trying to do anything I wanted to be sure the students had an accurate mental model of our solar system, our galaxy, and the universe as a whole. Without this mental map as a reference point, any learning would not be placed in meaningful context in relation to their place in the universe on earth.
I asked the students to form small groups and then draw on large sheets of A3 paper what they think the solar system, milky-way galaxy, and the universe looked like. They also had to include whatever other structures they already knew about (labelled) so that I could see what other prior knowledge they had.
The task (picture below) revealed that they had some idea of the structure but had generally learned some names of planets and structures without putting them into a mental 3D model in their minds. That's where we started the lesson - going from the small things in the universe up to the big things and how many of each there are. Then we slotted some other structures such as asteroids and gas clouds into the mix.
If I had time I would have asked them to repeat the formative pre-test to see the added value, but since we only had one lesson I informally polled the students to see what they had learned and found they had increased in knowledge and had enjoyed the process.
Some students who had shown they already grasped the main material I gave research projects on topics in astronomy of their own choice. This kept them interested and learning at their level.
