The billions of galaxies that make up the known universe come in a dazzling array of masses, shapes and colours. In the past few decades we’ve made incredible advances when it comes to observing these galaxies and better understanding how such diversity arose in the universe, yet our observations continue to surprise us.
To understand why galaxies look different, consider the fact that people, born in different parts of the world and going about their individual lives while interacting with different people, look different. Similarly, we find that the appearance of galaxies, ranging from the smallest with only a few thousand stars to the largest with more than a trillion times the mass of our Sun, are a product of the environment in which they form and the interactions they then have with other galaxies.
While people have some choice over the direction their lives take, the fate of galaxies is controlled by the all-permeating force of gravitational attraction. In many cases, this causes them to collide in spectacular fashion, leading to the formation of yet more massive galaxies. In other cases, a galaxy may be drawn towards the combined gravity of many other galaxies lying in a single gravitationally-bound structure known as a galaxy cluster.
Transforming Galaxies
The Coma Cluster,which lies 300 million light years from us, is a relatively...
