Our Sun is one of hundreds of billions of stars that make up the Milky Way galaxy. By studying other galaxies, astronomers learn more about the galaxy that we live in. Do all galaxies have the same shape? Are all galaxies the same size? Do they all have the same number of stars? How and when did galaxies form?

This lab uses pictures obtained by the Hubble Space Telescope and by telescopes on Earth to illustrate the spectacular variety of galaxies that exist in our universe. You will see how scientists classify different types of galaxies and have a chance to try it yourself. Occasionally, two galaxies may pass close enough to each other that they collide. Such collisions can result in a tremendous burst of star formation. Some scientists study the behavior of these "starbursts" to understand their role in galaxy evolution. You will see an example of this spectacular phenomenon in the Hubble image of the Antennae galaxies.

Begin this lab here. 

Write a summary of what you learned in this lab about how scientists classify galaxies.