International Astronomical Union

The International Astronomical Union (IAU) is like the boss of all astronomers. They are in charge of deciding things like what counts as a planet, what names to give to stars and galaxies, and how to measure time in space. Just like how your teacher decides what rules you have to follow in the classroom, the IAU makes rules for astronomers to follow. They have a big meeting every few years where astronomers from all over the world come together to talk about the latest space discoveries and vote on important decisions. Kind of like a big group project!