What a fantastic idea to use playdough to create the planets. I definitely think using the Planets as an Aistear theme almost or rather maybe constructing a Planets lesson and using the methodologies of Aistear to teach it would be particularly engaging for infant pupils and allow them to really discover and embrace all aspects of the planets. I also (despite my obsession with not mixing playdoughs usually!!!) love the idea of mixing the colours of the playdough to get the accurate colour for each planet and I think displaying these would make the pupils more proud of their work and also serve as a reference point for future learning.