Here is Oskar Pernefeldt's design for "The International Flag of Planet Earth." Also good for UN subagencies, atheist headstones, and the random output of logo generators for startups with inappropriately Asian names.
The mockup art is brilliantly Ballardian. Who does not appreciate the mounting excitement of being in an empty committee room when no-one else knows you're there?
Become a citizen! Do you want to know more?
Mars needs rimming.
On the plus side, it's not as if children will actually have to draw these things in the future.
Here's a how to!
Here is Eddie Izzard, explaining the cunning use of flags.
Here is the flag that we'll use to colonize the galaxy.