The world galaxy is such a small word for something that is about 580.000.000.000.000 miles across. The word galaxy means a organized system of about 10 million to in the trillions of stars mixed with gas and dust. Galaxies are classified in three groups. They are elliptical, spiral, and irregular galaxies in our universe. Now scientist believe that large black holes exist in the midde some develop galaxies. So watch out next time you are flying though space.
elliptical
The elliptical is thought of as being the oldest kind of the three. It has an elliptical or oval shape, and there is much more random star motion in it. There is also almost no to little dust and gas in between the stars. Bescause it is the oldest of the galaxies you want find many stars forming in it.
Examples of elliptical galaxies are M87 in the virgo cluster and M32 next to Andromeda.
spiral
The spiral galaxy is the teenager of the bunch. We live on our own spiral galaxy called the Milky Way. The spiral galaxy is more flat shape than the elliptical galaxy. It also has two arms spiraling on it. It kinda looks like a hurricane in a way. The spiral galaxy has more rotalional motion than random motion. It has more gas and dust between stars, and have forming stars in its arms.
Examples of the spiral galaxies are the Milky Way and the near by galaxy called Andromeda.
irregular
The last but not least is the irregular galaxy. It is the youngest and most likely the most common galaxy around. It has no definite shape of its own. Most irregular galaxies have a lot of gas and dust in them, but you will find little to no stars forming in them.
Examples of a irregular galaxy is LMC and SMC. They are two small galaxies that orbit the Milky Way.
I know this isn't much on galaxies so if you ever have any questions just e-mail me and I will answer it.
