Why are galaxies different shapes?

1 Answer
Apr 12, 2018

There are four different galaxy shape categories spiral, elliptical, lenticular, and irregular. See the explanation below to see why they are the way they are.


Galaxies have very dynamic shapes, meaning that they can change over time. For example, if a galaxy is left alone and undisturbed for a long time they become more flat, elliptical and spiral shapes whilst galaxies that have been disturbed, or rather, collided with another galaxy become more spherical and round.

So basically it is dependant on the Galaxy's surroundings and environment. If it had a rocky past it might be more spherical or irregular but after a few billion years it might have moved more towards a spiral shape.

Something to note is that small galaxies rarely form anything other than irregular shapes since their gravitational force isn't strong enough to form spiral or elliptical shapes.