Resources for high ability year 7 or middle ability year 8. Students have to find a suitable planet for Dave the alien using the planet list. The planet list has each planet with its weather, environment and distance from the sun. There is no correct answer, you could maybe adapt it so there is a successful story line for Dave the alien. Introduces AU (astronomical units) and accretion. I have undertaken this lesson myself and it was successful, students really liked the alien idea but it also gave them a chance to get familiar with the different conditions on each planet.