The Odd Couple: The Milky Way and Andromeda's Upcoming Collision
The Milky Way is set to collide with its neighboring galaxy, Andromeda, in about 4.5 billion years from now. This event, which is expected to last for billions of years, is of great interest to astronomers and stargazers alike.
What is the Milky Way?
The Milky Way is a barred spiral galaxy that is home to our solar system, as well as billions of other stars, planets, and celestial bodies. It is estimated to be about 100,000 light-years in diameter and contains around 100 billion stars. Our galaxy also has a supermassive black hole at its center, which is believed to be over 4 million times the mass of our sun.
What is Andromeda?
Andromeda, also known as Messier 31 or M31, is a spiral galaxy that is located about 2.5 million light-years away from us. It is slightly larger than the Milky Way and is believed to contain over a trillion stars. Andromeda is also home to a supermassive black hole, which is thought to be around 140 million times the mass of our sun.
When Will They Collide?
The Milky Way and Andromeda are currently moving towards each other at a rate of about 250,000 miles per hour. Although 4.5 billion years seems like a long time, in the grand scheme of things, it is just a blink of an eye in the universe.
When the galaxies collide, the stars within each galaxy will be thrown into new orbits around the combined black hole at the center of the two galaxies. Over time, these stars will eventually settle into a new stable orbit, creating a brand new galaxy.
What Will Happen to Earth?
Although the collision between the Milky Way and Andromeda sounds catastrophic, it is unlikely that anything will happen to our solar system or to Earth. This is because the distance between stars in galaxies is so vast that it is unlikely for two stars to collide. Additionally, our sun is expected to undergo a process called a "red giant phase" long before the collision takes place, which will cause it to expand and swallow up any planets that are too close.
The upcoming collision between the Milky Way and Andromeda is one of the most exciting astronomical events in the foreseeable future. While we won't be around to see it, the idea of two galaxies merging into one is truly awe-inspiring.