Stars grow up, just like you. They go through changes that shape the universe. 

This is a spiral galaxy. Spiral galaxies look like pinwheels, and have distinct stars. The Milky Way, where Earth sits, is a spiral galaxy. We are one of many, many galaxies. The earth is on an arm of the spiral.            

This is an irregular galaxy. Irregular galaxies don't have any particular shape. They look like puffs of smoke or clouds.

This is an elliptical galaxy. Elliptical galaxies are roundish, and 3D. Unlike a spiral galaxy, these galaxies don't typically have any stand out features or star clusters. 

Now that we've learned about the galaxies, we can learn about the stars inside of them. On page 11, you can see a map of a stars life from birth to death. Stars spend most of their life in something called main sequence. Main sequence is like adulthood for a star. Our sun is in main sequence.

Let's begin our journey with a star's place of birth, a nebula. Nebulas are made of dust, hydrogen, and helium. When a nebula gets too large the gravity causes the nebula to collapse. and makes a hot, high mass object-a star.

When a star forms in a nebula, it can start life as an average star, or a massive star, each star will go onto a completely different life.