Milky Way May Not Collide With Andromeda, New Study Suggests

For decades, astronomers have anticipated a collision between the Milky Way galaxy and its largest neighbour, the Andromeda galaxy. The cosmic clash has been predicted to take place in about 4.5 billion years. This age-old belief, dubbed “Milkomeda,” has now been challenged by a new research suggesting that the two galaxies might not be on the course of a collision.

Milky Way and Andromeda are separated from each other by nearly 2.5 million light-years. For a long time, scientists have believed that the two of them are headed for a collision, which will eventually merge them into an elongated galaxy. The reason behind this is that they are moving towards each other at nearly 2,23,694 miles per hour, which is roughly 100 km per second, CNN reported.

Taking into consideration the latest data from the Hubble and Gaia space telescopes, the new study—published by Nature Astronomy—indicates that there is only about a 2% chance of a collision between the two galaxies within the next four to five billion years.

Also, there is about a 50% chance of a collision between them in the next 10 billion years.

This came out after factoring in the gravitational pull of Local Group galaxies, besides running one lakh simulations using the new data from the space telescopes.

The Local Group features 100 known smaller galaxies. It also includes the Large Magellanic Cloud (LMC) and the Triangulum galaxy.

The astronomers have factored some of the largest among them to witness their role in our galaxy’s future during the next 10 billion years. Their study was published in the Nature Astronomy journal on Monday.

“Until now, we thought this was the fate that awaited our Milky Way galaxy. We now know that there is a very good chance that we may avoid that scary destiny," said co-author of the study Carlos Frenk, a professor at Durham University in England.

Lead author Dr Till Sawala, astronomer at the University of Helsinki in Finland, suggests that the merger could involve a "strong starburst, during which many new stars would form".

This will be followed by an intense radiation period caused by exploding young stars. Eventually, the supermassive black hole will shut down star formation "completely,” Sawala added.

Sawala suggests that a few billion years later, traces of the Milky Way and Andromeda would disappear.

Andromeda is placed 2.5 million light years away from the Milky Way. 

The galaxy is said to be the home of at least a trillion stars. In comparison, our galaxy hosts 100-400 billion stars.