The Cartwheel Galaxy (also known as ESO 350-40) is a lenticular and ring galaxy about 500 million light-years away in the constellation Sculptor. The ring resulted from a collision between two galaxies that would have been observed for the first time on Earth at the beginning of the Jurassic Period 200 million years ago. What we see today took 200 million years to develop, based on rate analysis of expanding gases.

Image Credit: NASA