Learning about galaxies, including our own, includes a lot of investigation into the shapes of the galaxies which is an especially fun project for kids. A lot of what we know about galaxies in the universe has to do with their shapes and the way they appear to us. It is important that children understand and are able to recognize the different shapes of the galaxies, especially when it comes time to study our own galaxy.
Use this guide and activity suggestions to help children learn about the different galaxy shapes that can be identified in the universe. Make sure to talk about how we are able to see and identify each of the different galaxy shapes.
Identifying Basic Galaxy Shapes
There are three basic galaxy shapes that galaxies big and small are classified into– Elliptical, Spiral and Irregular. The spiral is the most commonly found galaxy shape and the most distinctive which is the shape of the galaxy that we live in. Spirals have a central point, with several arms that radiate out and create a spiral effect. Elliptical galaxies are also known as dying galaxies because there is no new star birth occurring within their perimeter, but they are some of the brightest densest galaxies out there.
Finally, irregular galaxies describe galaxies of all other shapes. Some of them appear to have been spirals or elliptical at one point or another, but have now been torn apart or changed in some way. An interesting group of galaxies, the doubles, resides in this category and they appear to be two galaxies that have combined to form one large galaxy with a double center, or one center pulling the other one into it.
Explore Galaxy Photos
The best collection of galaxy photos is located on the official Hubble Telescope site. Here you can find photos that Hubble has been taking of our universe for several years, but the galaxy page is what we want to look at right now. Flip through several of the photos in this gallery (http://hubblesite.org/gallery/album/galaxy/) and see if students are able to identify the basic shapes of the galaxies they are looking at.
What Other Proof Of Shape Exists
Hubble is able to bring back some pretty incredible images, but there are some things in deep space that are hard for even Hubble to see. By observing the characteristics of the galaxies that we can see, we are able to distinguish the shapes of the galaxies that are too far to get a clear picture of. Solid masses are most often elliptical galaxies, and when we are able to see a line with a slight bulge in the center, we know that this is indicative of a spiral galaxy. The motion, which can be detected by looking at several frames from each shot help with a magnifying glass.
As you mark the changes you can begin to see that the stars are moving in a spiral or not. The rate at which everything is moving is important too, because faster motion means a galaxy that is spiraled and moving fast to feed more energy into its center. Do this with several distant galaxy pictures and see if you can catch which hard to distinguish galaxies you are looking at- spiral, elliptical or irregular.
Have your child/students draw their own galaxies based on what they’ve learned above! Get creative and break out the canvas and paints to create a masterpiece!