Currently, the distance between Andromeda and the Milky Way is 2.5 million light years. They belong to the Local Group, which includes over 50 galaxies. The Local Group is about 4 million light years in diameter.
The largest galaxy is Andromeda, our second largest Milky Way. In 4.5 billion years, there will be a kind of gradual unification into one future huge Milkomed galaxy.
If humanity can survive for another 3 billion years, then it will already see the approaching Andromeda with the naked eye. This will be the first bell for the sunset of the Milky Way.
At first, on the celestial horizon, the spiral disk of Andromeda will be vague, unclear. Gradually, the visibility will become clearer, the disk will begin to fill the heavenly space. The space will sparkle with star flares, the night sky will become brighter.
Although both galaxies have several hundred billion stars, a collision of the solar system with any Andromeda star is unlikely due to the too large distances between the stars.
After computer simulations, scientists made an analysis, the probability that the solar system will be captured by Andromeda is ~ 3%. It is much more likely, 12%, that the system will quickly leave Milkomeda due to the forces of gravity.
In this case, the inhabitants of the Earth will no longer see the usual starry sky. The number of stars in the sky will decrease. There will be a feeling that we are alone in this world. But further existence is possible. The solar system will continue to be protected from cosmic rays by the magnetosphere.
Only humanity is unlikely to be concerned about the consequences of collisions between the main galaxies of the Local Group. At this moment, the Sun will begin to move into the stage of a red giant. We’ll either have to leave the planet or come up with a method to move the Earth away from the Sun.
In the remaining 85% of cases, the Sun will remain in the composition of Milkomeda. The collision will not affect the solar system in any way. Only stunning views and nothing more.