Orla,
have you a suggested source for planet colouring? You could use the Tiny Little Book of the Planets that was shared in Module 2, which includes simple facts.
They wouldn’t quite be flashcards, so have you a suggested place to find those, or have you made some that you might share? Armagh Observatory & Planetarium have some that could be adapted to be a bit simpler for use with younger children, I think these would be better for 3rd class+ (https://s3.eu-west-1.wasabisys.com/armagh.space/site/wp-content/uploads/2021/03/19133706/AOPS-Guide-to-the-Solar-System-FINAL-min.pdf)
Cork Art Supplies (and other craft or home shops, the Range is good, and Baker Ross have this one) have a range of sytrofoam balls, but would you look at the mathematics of measures and have the children select their own?
This would allow access to Mathematics> Measure:
Chooses an object from a group of objects for a purpose based on a particular attribute