Galaxies

Image courtesy of NASA

You may have started this topic thinking that there were just a few galaxies in the universe. Now you know that there are many galaxies, and they are found as three basic galaxy types, which differ in their shape. Galaxies change during their lifetime. Many billions of years from now, the Milky Way Galaxy is expected to collide with the much larger Andromeda Galaxy. By observing galaxies and their properties, astronomers hope to learn more about these collisions.