What happens depends on the masses of the two galaxies involved and how close they are when they collide or nearly collide. As in a wrestling match, size matters. When a small galaxy meets a large one, the small one often loses. It can be stripped of much of its matter and energy, or it can be swallowed whole. Collisions between two large galaxies, however, often result in a stalemate of sorts, as the two galaxies become one.
Galactic collisions can spur rapid star birth as gas clouds are heated and compressed.
In this image, a collision has triggered the birth of new stars in brilliant blue clusters, the brightest of which contains roughly a million stars. Our own Milky Way galaxy is thought to be a barred spiral. However, once in awhile, a large galaxy may encounter another large galaxy. The result may be the merger of these galaxies, forming a single elliptical galaxy. The ez editorial policy and how to respond Write to us, and see your comments posted here.