Dark matter is super important for understanding how our universe is shaped.

Did you know that dark matter makes up about 27% of everything in the universe? That's a big chunk! In comparison, the regular stuff we see, like stars and planets, only makes up about 5%. The rest, which is around 68%, is called dark energy.

Let’s break down why dark matter matters:

1. Gravitational Influence:

   • Dark matter’s gravity helps hold galaxies together.
   • It also affects how galaxies form and move.
   • When scientists look at how fast stars spin in galaxies, they see that stars on the edges move faster than we expect. This hints at a lot of mass we can’t see.

2. Large Scale Structure:

   • When scientists create models of how the universe grows, including dark matter, these models look a lot like what we actually see.
   • The way galaxies are arranged, with long threads and empty spaces in between, is mostly shaped by dark matter's pull.

In short, dark matter is key to understanding how galaxies form and how everything in the universe works together.