Is happening, the Milky Way has been torn by the Magellanic Galaxy, which will threaten the earth in 2 billion years.

With the expansion of space, the distance between galaxies will be farther and farther, and this relationship is that the farther away the galaxy is from us, the faster it will be away from us.

The fact that the universe is expanding was obtained by Hubble in 1929 by observing the variable stars in the galaxy and the fact that the starlight is redshifted. That is to say, in the future, our universe will expand into a larger space, and the density of matter inside will be lower and lower;

When all the galaxies are gradually moving away from us, their speed of moving away from us will gradually exceed that of the filaments, which means that most of the galaxies we can see now will disappear from our sight in the future.

but besides the expansion of the universe, another fact is happening. That is, the universe is experiencing the merger of galaxies all the time, and our galaxy will experience the same fate in the future.

you may be puzzled. didn't you just say that the universe is expanding? Galaxies should be far away from each other, so why do galaxies merge in the universe?

The expansion of the universe is true, and there is nothing wrong with galaxies being far away, but don't forget that the matter in the universe also forms many large structures under the action of gravity.

For example, our solar system is an eye in the Milky Way. It is affected by the gravity of the center of the Milky Way, and the space is expanding, but it will not break up the gravitational relationship between the solar system and the Milky Way.

The same Milky Way and Andromeda galaxies, as well as dozens of galaxies such as Triangle and Magellanic Cloud, also form a big family under the action of gravity, which is called local galaxy group.

In this galaxy group, except for the central position of the Milky Way and Andromeda galaxy, all the dwarf planets revolve around these two galaxies, among which the large and small Magellanic galaxies are the satellite galaxies of the Milky Way and revolve around the Milky Way.

it is obvious that gravitational structures like local galaxy groups cannot be dismantled by the expansion of the universe. In the universe, it is these galaxies that have been bound by gravity, and they will all merge into a larger elliptical galaxy in the future.

Therefore, it can be predicted that all the galaxies in the local galaxy group will merge together in the future. It is estimated that the time for the large and small Magellanic galaxies to collide and merge with the Milky Way will be about 2 billion years later, and the time for Andromeda to collide with the Milky Way will be about 3.7 billion years later. The larger galaxy structure formed by these merging times will gradually sweep all the surrounding galaxies under the action of gravity.

At that time, the local galaxy group will become a galaxy, and we can call it Fairy-Milky Way. With the expansion of the universe, those galaxies that are not comfortable by gravity will gradually move away from us and disappear.

If there are intelligent life on the earth at that time, all the celestial bodies they saw in the sky and all the events that happened will be within the range of Fairy-Galaxy.

if they look out of their own galaxy, they will find that the universe is dark and there is nothing except their own galaxy. At that time, they will come to the conclusion that there is only one galaxy in the universe except the endless dark space ... < P > A paper recently published in Nature Astronomy shows that the Large Magellanic Cloud has begun to influence the movement and structure of the Milky Way.

scientists have found that the gas and dust at the edge of the Milky Way galaxy have been pulled by the strong gravity of the dark matter halo of the Large Magellanic Cloud orbiting it, which has changed its shape.

However, this discovery does not mean that the two galaxies will merge, but that the Large Magellanic Cloud normally passes quickly from the position closest to the Milky Way (5Kpc, about 16, light years), which gives a gravitational impression on the structure of the Milky Way.

Moreover, it will not affect the overall structure of the Milky Way at such a long distance. After all, the mass of the Milky Way is 1 times larger than that of the Large Magellanic Cloud. Even if it collides and merges, it must be that the Large Magellanic Cloud was first disintegrated by the powerful tidal gravity of the Milky Way and then swallowed up.

scientists say that this discovery can help us understand the influence of the large Magellanic galaxy on the movement and knot structure of the Milky Way when it passed through the Milky Way in history.

The Large Magellanic Cloud is moving very fast when it passes the Milky Way, reaching 37 kilometers per second, and it is rapidly pulling and pulling the materials around the Milky Way.

The material around the Milky Way galaxy is pulled out, torn and even twisted. By observing the gravitational interaction between the two galaxies, we can model the gravitational force of the Milky Way and the Large Magellanic Cloud in the future and study the dark matter distribution of the two galaxies.

then you must be more concerned about what will happen when two galaxies merge? Will it affect the earth?

Galaxies are star islands in the universe, which contain hundreds of billions of stars, as well as star remnants such as black holes, neutron stars and white dwarfs, and gas and dust with a larger proportion of mass. Therefore, the merger of galaxies is the biggest super event in the universe.

we don't know what will happen when our galaxy merges with the large Magellanic galaxy and Andromeda galaxy in the future. But we can see what will happen to our galaxy in the future by looking at the merger events that are happening in the universe now!

The largest galaxy in the middle of the above picture is NGC 6872, which is four times the mass of the Milky Way, and the small galaxy in the lower right is IC 497, which is about the same size as the Milky Way.

The merger of these two galaxies was photographed by Gemini telescope.

The position of the red arrow in the above picture clearly shows that the stars and gas at the spiral tail of galaxy NGC 6872 have been pulled out by gravity.

It's like the Large Magellanic Cloud pulling the material at the edge of the Milky Way, but it's not so serious.

As you can see from the above picture, there are very bright radio sources in the center of two galaxies, which are actually black holes in the center of the galaxy. However, there are two radio sources in the center of IC 497, which shows that there are two black holes around it.

In the future, when these two galaxies merge, these three black holes will merge together to form a larger and more active black hole.

in addition to the above two merging galaxies, there are many merging galaxies in the universe. When two galaxies merge, the spiral structure before the galaxy will be destroyed because of the disturbance of gravity, which will make the running speed position of stars in the galaxy change greatly.

That is to say, if our Milky Way and other galaxies merge in the future, the constellations we see in the sky will deform quickly in a short time.

And when two galaxies merge, the gas in the galaxy will quickly form new stars due to the disturbance of gravity, and the star formation process of the whole galaxy will be very fast and intense, making the galaxy become a starburst galaxy;

Not only the speed of star formation is fast, but also the speed of death will be accelerated, and the speed of merger of neutron stars and white dwarfs will also be accelerated, resulting in frequent and rapid supernova explosions throughout the galaxy.

By then, our sky will look as bright as during the day.

The picture above shows that when the Milky Way and Andromeda galaxy merge, we will see the scene on the earth, because the matter in the galaxy will be very chaotic when the collision occurs, and it will take a long time to recombine;

At that time, the probability that some stray celestial bodies will break into the solar system will greatly increase, which will affect the stability of the orbits of celestial bodies in the solar system and certainly pose a threat to the earth.

Without the influence of alien celestial bodies, high-frequency high-energy events in galaxies will also cause great radiation harm to the earth, and life on the earth will certainly be restless.

most importantly, a research team concluded in 219 that the large Magellanic Cloud will activate the black hole in the center of the Milky Way after merging with the Milky Way about 2 billion years later, because there is also a black hole with a mass of 2 million times that of the sun in the center of the large Magellanic Cloud.

the merger of two black holes, coupled with the reorganization of galactic matter, will make the merged black hole become a super black hole with frequent material jets.

The merged galaxy has an active galactic nucleus or quasar. This is not a good thing for the earth.