Our galaxy, the Milky Way galaxy, is one of many many galaxies in the universe. Not all galaxies are the same though. There are many different shapes, elliptical, spiral, irregular, and sort of blob-like. How do you tell each apart? Well each galaxy type has their own characteristics: Spiral galaxies are pretty large, have spiral arms, are in a disk shape, and have dust. Elliptical galaxies are smaller, brighter, but have no arms or dust. In an article on universetoday.com called “The Milky Way and Andromeda“, it explains how the two galaxies are very similar but also have their own differences. Andromeda is the closest spiral galaxy to the Milky Way and can be see with the naked eye if in good conditions. Unlike the Milky Way which is about 150,000 light years in diameter, the Andromeda galaxy is 220,000 light years in diameter! It contains trillions of stars compared to our galaxies 500 billion stars. Unlike every other galaxy, Andromeda is moving toward us and will eventually collide with our galaxy in 3 billion years.
In our lecture tutorial on page 139, we had to classify different galaxies that were found on the last page of our book. We had to decipher which galaxy was a spiral and which was an elliptical. We also had to determine which ones seemed more red and others more blue. Red galaxies mean there are older stars in it and blue galaxies mean that there are new stars and active star formation. This article correlates to our conceptual objective 16 I can compare the Milky Way Galaxy to other galaxies. It explains similarities and differences in the Milky Way and Andromeda galaxy. Even though both have the same shape, each galaxy are different in their own way.
I liked reading this article because I didn’t know much about other galaxies besides our own. I never knew the Andromeda galaxy was moving toward us and will eventually collide with us. It seems like a scary thought but it won’t happen for a long time. Reading this article helped me understand more about this conceptual objective and about galaxies.