To introduce a lesson I would read Aliens love Underpants with the class.
After this We would talk about the aliens in the story and what you think an alien would look like. I would encourage children to be very creative here by asking them questions such as “How many legs does the alien have?” and “What colour is the aliens body?’
I would pass out modelling clay to each group- different colours placed at each table and ask the children to make their own alien/martian.
To conclude this lesson the children would come up to the front of the class and show off their alien and the other children would say something they liked about the alien. The children would then be asked to find one other person who had the same colour or features and we would talk about the similarities and differences reminding children that we are all unique.