Emily Chan
The fate of the Milky Way is much less certain than previously believed. Astronomers have been confident that our galaxy is destined to collide with its closest large neighbor, the Andromeda galaxy.
This cosmic event was anticipated to take place in roughly five billion years and has been considered to be unavoidable. However, a recent study is now questioning this widely accepted belief.
An international team of researchers led by Till Sawala from the University of Helsinki in Finland has found that there’s only about a 50 percent chance that the Milky Way and Andromeda will crash into each other within the next 10 billion years.
To come to this conclusion, they used the newest measurements of the velocities, masses, and positions of the Milky Way, Andromeda (also known as M31), the Triangulum galaxy (M33), and the Large Magellanic Cloud (LMC) to create a more accurate model of their interactions over billions of years.
The LMC is a satellite galaxy of the Milky Way. The researchers discovered that even though it is much smaller than the Milky Way and Andromeda, LMC’s gravitational influence is strong enough to possibly throw the Milky Way off the collision course with Andromeda.
When including the LMC in their calculations, the likelihood of a Milky Way and Andromeda collision actually decreased.
The new research shows how much of an impact that smaller galaxies can have on larger ones. It also points to the significance of accurate measurements in astronomy.
Even when measurements are slightly off, it can lead to completely different results, especially when you’re trying to predict cosmic events billions of years into the future.
For instance, small changes in Andromeda’s proper motion could result in a range of outcomes, from an almost definite collision to virtually no chance of a merger at all.
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