Galaxy groups and clusters

Okay, imagine there are lots of stars in the sky (you might have seen them on a clear night). A galaxy is like a big family of stars that are all hanging out together. But sometimes, galaxies get very close to each other and they start to form groups. This is like when you and your friends all get together and become a group.

Now, when even more galaxies come together and form a REALLY big group, we call that a cluster. This is like when your group of friends meets up with another group of friends at the park and you all become one big group.

Galaxy groups and clusters can have hundreds or even thousands of galaxies in them! They all hang out together and sometimes even merge together to become one giant galaxy.

Scientists study galaxy groups and clusters to learn more about how the universe works and how galaxies are formed. It's a really fascinating topic!