> Which type of galaxy is the Milky Way galaxy?And the answer: spiral.The Milky Way galaxy is a huge collection of stars, gas, and dust – our sun isjust one of billions of stars swirling within the galaxy. If you look at theMilky Way from the top or bottom, it would look like a spinning pinwheel, whichis why it's considered a spiral galaxy. It's estimated that two-thirds ofgalaxies in the universe are spiral in shape.Photo credit: spacetelescope.org.In the last century, we've learned quite a lotabout our galaxy and those which surround it. Each galaxy is a collection ofhundreds of millions (or even trillions) of stars, ranging in size from tens ofthousands to hundreds of thousands of light-years across, and come in a varietyof shapes. Besides the spiral formation with which we're more familiar, thereare three other broad categories of galaxy shape: elliptical, peculiar, andirregular.Spiral galaxies are characterized by broad, flat, rotating disks of stars, gas,and dust. The stars closer to the central bulge of the galaxy tend to beyounger, redder stars, while those in the extended arms of the spiral are olderand bluer. When we view these galaxies edge-on, we can observe the flat,disk-shape that is likely a result of their formation from clouds of dust andgas billions of years ago. Elliptical galaxies are, well, elliptical in shape. Some are nearly spherical,resembling gigantic cotton balls of stars, while others are more elongated andresemble an American football. These galaxies lack distinct structure, and tendto appear puffier. Elliptical galaxies are also characterized by a lack of gasand dust, and are often populated with older stars. It's unclear how ellipticalgalaxies form, but scientists currently believe that they are the result ofgiant, galactic collisions. Peculiar galaxies are essentially all due to collisions. Oftentimes, remnants ofthese collisions can be observed in parts throughout their whole, as smallergalaxies will draw in stars before flinging them away. This can result in ashape called a ring galaxy, with the culprit star in the center. Finally, irregular galaxies are exactly what they're named for: small,shapeless, chaotically arranged galaxies that can be victims of collisions butare distorted to the point of an unrecognizable shape. Learn more about galaxies below.