Hi Louise this seems like a fun activity and potential for so many more lessons. With the ball and flashlight you can go and teach about shadows and activities can include making shadows with their hands, tracing their shadows in pairs outside with the Sun, etc.
Pictures and vocab is very important especially as most children are visual learners. And I for one am always amazed doing a KWL chart at the amount of information children know about a topic beforehand and how much info they gather in such a short time. There will always be a space lover in the group of children you’re teaching, or at least one will be born after the topics are taught.