A lot of us wonder what happens when two galaxies collide in the universe? The truth largely depends on the size and composition of the constellations that are about to collide. Today, scientists explain that the best way to think about the meeting of the galaxies is to think of them as ‘merging’ rather than ‘colliding.’ Additionally, planets and stars will never run into each other. Why? Simply because it is one of the principles of the infinite universe.
Furthermore, galaxies contain a lot of space; therefore, it is more likely that stars will just pass by. It is possible that many large galaxies can attract smaller galaxies. The gravity possessed by the larger galaxy will pull the smaller galaxy towards it, creating a collision. If one of the two galaxies has enough momentum, the galaxy with enough movement will keep moving away after the collision. However, when most galaxies are being pulled towards each other, it is highly unlikely that they will simply pass through each other as the momentum is not enough, and the gravitational pulls are too strong to escape.
This means larger galaxies begin to change into a smaller one and merge this small galaxy into the larger one. Moreover, galaxies are made of material, gas, stars, dust, and rock. Upon merging of the galaxies, the gasses interact with each other. The gasses in galaxies are spread around in the galaxy system like clouds. This again means that large gas clouds are more likely to run into other large clouds of gas. As a result, the gases become dense and undergo intense pressure. This leads to the creation of gas waves that can collapse them. Ultimately, both of these actions cause new stars to form.
When two galaxies of the same size are merging, many new stars are formed, making the galaxies even brighter. However, if the merging happens too quickly, then chances are that the newly formed stars will die shortly after they have formed. The merging process can create a new super galaxy. In this new super galaxy, stars will probably move to new locations. More so, it should be kept in mind that these merges can take billions of years to complete. The Milky Way galaxy and the Andromeda are moving towards their collision course, but it will take millions of years for them to collide. Scientists are off the view that the black holes existing in both galaxies will combine as well, but there is no saying about how it will affect the rest of the galaxy.
Galactic collisions have been simulated by computer (the calculations would have been virtually impossible in pre-computer days). These simulations show, step by step, how two galaxies collide with each other. As a relatively compact galaxy passes through a normal spiral one, the combined gravitational pull of their overlapping centers draws the spiral’s stars and gases inward. Then, as the interloper passes through and away, gravity lets up. Stars and dust are released to bounce back, resulting in a wave that carries galactic matter outward in a ring shape.
The computer also tells us that the ring galaxy will be unstable. Unlike the rings of the Saturn, the galactic material has no giant planet to orbit. In time, the ring galaxy may break into three to six separate galaxies. This is probably the origin of some galaxy groups we see today. A ring galaxy does not form overnight. Estimates put the time involved at about 100 million years. Surprisingly, such a galactic encounter will result in very few star-to-star collisions. Stars are too far apart in galaxies for crashes to be at all likely. And collisions between galaxies are so rare, there’s little chance we will ever see one in progress.
To conclude, when thinking about the collision of two galaxies, do not think about objects smashing into each other or any violent crashes. Instead, think of it as a merging process in which both galaxies lose their shape and create a new super galaxy that is elliptical.
- Interacting galaxy (Wikipedia)