Here is a link to the ‘Design a Planet’ resource from the IOP, part of a set of 3 Creative Physics activities which could be used in the classroom, for STEM Clubs or at outreach events.
http://www.iop.org/activity/outreach/resources/activity/creative/page_53877.html
In the other 2 activies you can make a ‘Particle Collision Mobile’ and a ‘Galaxy Suncatcher’
Have fun!