Final answer:
The Milky Way and Andromeda galaxies are set to collide in about 3 to 4 billion years, eventually forming a larger elliptical galaxy. The collision will spur new star formation and dramatically reshape the structure of both galaxies without direct star collisions.
Step-by-step explanation:
When the Milky Way collides with the Andromeda galaxy, a process that is expected to start in about 3 to 4 billion years, it will initiate a long sequence of gravitational interactions. According to computer simulations, the two galaxies will engage in a complex dance, gravitationally pulling on each other, warping their shapes, and triggering new star formation. Over time, the galaxies will repeatedly collide and separate before eventually merging into a single, much larger, and more rounded elliptical galaxy. This cosmic event is unlikely to result in direct collisions between stars due to the vast distances between them, but it will significantly alter the structure of the galaxies.
This merger is part of a natural evolution observed in galaxies across the universe, and it will conclude with the formation of an elliptical galaxy whose combined brightness from the cores will illuminate the night sky dramatically. The Sun's location in relation to the galactic center may change as orbits within the merging galaxies are adjusted throughout this grand collision.