From NASA, here’s a vivid look at the future of our Milky Way in an ultra high-end computer simulation of spiral galaxies colliding. Collisions and mergers are central to galaxy evolution, from the earliest dwarf galaxies that formed to the familiar galaxies we see today. These collisions in action will be targets for the James Webb Telescope. Astronomers hope to understand how the shape, structure and chemical content of galaxies change over the sweep of cosmic history.