Milky Way and Andromeda Galaxies are neighboring galaxies of each other. We live in the milky way galaxy and we can call this galaxy our home. The Milky Way Galaxy is actually a Spiral Galaxy. Our solar system is on the outer side of this galaxy. If you go to the dark side on a summer night, the band of stars you see in the sky will be about 5% of our Milky Way galaxy. After 4 billion years, the Milky Way and Andromeda Galaxies collided. What will be left of our milky way galaxy after this collision?
Today, we know that there are billions of galaxies in our universe, but a hundred years ago, we thought that our own galaxy, the Milky Way, was the entire universe.
We used to see some Nebulas like this. This is the Andromeda Nebula. At that time we thought that actually this nebula is quite small and is part of our universe (Milky Way). But when an astronomer saw the distance of this nebula in 1920, its size was 2.5 million light years away. This meant that he is actually visible to us but his size is much larger. Today we know that Andromeda is a galaxy and the stars in it are much, much more than the stars in our galaxy.
The Andromeda Galaxy is the closest galaxy to our Milky Way galaxy. Therefore, the Milky Way and Andromeda Galaxies are neighboring galaxies. The Andromeda Galaxy is also a spiral galaxy and looks exactly like the Milky Way Galaxy. You can easily see it with naked eyes at night.
We See Past of Andromeda Galaxy
We can see the Andromeda Galaxy with our naked eye without a telescope, even without binoculars if you are on the dark side. When you look at the Andromeda Galaxy, you will see a batch of its light, its photons that went on when there were no humans on our earth. So, the Andromeda Galaxy that you see in the sky at night is not actually the present of Andromeda Galaxy, but you are seeing its past.
Collision of Andromeda and Milky Way Galaxies
The distance between Milky Way and Andromeda Galaxies is very large but it is not a problem because Andromeda and Milky Way Galaxies are coming towards each other very fast but their speed of approaching each other is about 400,000 KM/HR but their distance is still so great that it will take about 4 billion years for the Andromeda and Milky Way Galaxies to collide.
Why Milky Way and Andromeda Galaxies Will Collide?
Here comes a question that the universe is expanding, every star is moving away from each other and similarly every galaxy is also moving away from each other. But why are the Milky Way and Andromeda Galaxies approaching each other? The answer is gravity, because gravity overcomes the expansion of the universe because their mass and distance are relatively close. Such galaxies collision is quite common in the universe.
You are looking at the image above. In this image, you are seeing a collision of several galaxies. They take millions and billions of years in real time, but if astronomers see the collision of different types of galaxies, they can piece together what kind of collision of Milky Way and Andromeda Galaxies will be in the future. Not only this, but astronomers can also use simulations of how our Milky Way and Andromeda Galaxies will survive after this collision.
After Collision of these Galaxies
When the Milky Way and Andromeda Galaxies will collide with each other after 4 billion years. The Andromeda and Milky Way Galaxies will pass each other. At that time, a very beautiful dance of galaxies will be seen in the sky.
After this collision, the spiral arms of the Milky Way and Andromeda Galaxies will end. Astronomers nickname it MILKDROMEDA. Because it is a combination of Milky Way and Andromeda Galaxies.
If you are wondering what will happen to our stars after this collision and what will happen to our earth then it will collide with each other but it will not happen at all no star or planet will move from its place. Because the reason behind this is that the distance between the stars is very large for their size.
When the Milky Way and Andromeda Galaxies collide, all these stars will pass through their spiral arms. But some objects must collide, which are the supermassive black holes between the Milky Way and Andromeda Galaxies. Because there are supermassive black holes between the two galaxies, when the Andromeda and Milky Way Galaxies collide, these two supermassive black holes will merge.
New Stars Forming Due to Collisions
When Milky Way and Andromeda Galaxies collide, another thing that will collide is the gas cloud or magellanic clouds of Andromeda and Milky Way Galaxies. When these clouds collide with each other, then billions of stars will be formed.
When the Milky Way and Andromeda Galaxies are close to colliding with each other, the Andromeda Galaxy will be visible in the sky at that time.
Today, Andromeda Galaxy looks very small, but after 2 billion years from today, you will see it like this, and after 4 billion years, Andromeda Galaxy will start to collide with our Milky Way Galaxy. At that time, our sky will be red, blue, Green, white, brown colors will appear.
At that time, the sun will also begin to expand and it will be in its red giant stage, during this time the water of the earth’s sea will also become steam and fly away, then humans will not be alive on earth at that time. If we have any descendants, they will be in the hands of another star and they will be seeing these beautiful sights. But after 7 billion years from today, the spiral pattern of Andromeda and Milky Way Galaxies will be completely gone.