The Andromeda Galaxy, also known as M31, is the closest spiral galaxy to our Milky Way galaxy. It is currently approaching our galaxy, and astronomers predict that a collision between the Milky Way and Andromeda is likely to occur in the future.
Based on current estimates, it is projected that the Milky Way and Andromeda will collide in about 4.5 billion years from now. This event is sometimes referred to as the "Andromeda-Milky Way collision" or "Milkomeda." However, it's important to note that these estimates are subject to change as our understanding of the dynamics of galaxies improves.
When the collision occurs, the two galaxies will begin to merge over a span of hundreds of millions of years. The exact outcome of this collision is complex and still under study. It is expected that the stars in both galaxies will not collide with each other individually due to the vast distances between them. However, the gravitational interactions will distort and reshape both galaxies, and new star formation may be triggered as gas and dust clouds interact.
Ultimately, the merger will result in the formation of a new galaxy, sometimes referred to as "Milkomeda" or a "Milkomeda elliptical." The resulting galaxy will be a hybrid of the Milky Way and Andromeda, with a different structure and appearance compared to its precursor galaxies.
It's worth noting that over such vast timescales, many other cosmic events and changes will occur, so the future state of our solar system and the Andromeda Galaxy will depend on numerous factors.