Here's why:

* Constellations are patterns of stars as seen from Earth. They are not physical groupings of stars in space.

* Galaxies are vast collections of stars, gas, and dust held together by gravity. They can be millions or billions of light-years across.

We use constellations as a way to map the night sky, and we often describe the location of a galaxy in relation to a constellation. For example, we might say "the Andromeda Galaxy is located in the constellation Andromeda," but that doesn't mean the galaxy is *inside* the constellation.

Think of it like this: You can see the moon in the constellation Orion, but the moon is not a part of Orion. The moon is simply passing through the region of the sky we call Orion.