In this activity, learners design a flag for a chosen or assigned planet. The instructions include information about flags on Earth, and a list of flag references. Learners can gather information about their planet online at www.nineplanets.org, which is similar to what's on the "Planet cards" sold by Family ASTRO. There is an extension discussion about whether the planets should become private property eventually, or perhaps be jointly owned by all of humanity. This activity targets families but can be adapted for any group of learners working together.