The centerpiece of any birthday party, the cake, is your top priority. Thankfully, you get cakes in various shapes and sizes, or bakers are willing to create them to your specifications. There are many ideas for an outer space-themed cake, like a Rocket Cake, Moon Cake, Robot Cake, Solar System Cake, and the like.
To lend authenticity to your outer space-themed party, try some real freeze dried space ice cream. Since they are naturally shaped like flying saucers and planets, donuts and holes make the perfect food for this theme. Almond rocks or any chocolate covered in silver foil would create the ultimate moon rocks.
Paint two plastic soda bottles silver and stick them together side to side. Use string for shoulder straps, and voila!!!! Add red and yellow paper or cloth into the mouth of the bottle to look like flames. You can also create a rocket ship out of a large cardboard box, with cutouts for portholes. Makes for the perfect photo opportunity.