New Insights on the Milky Way and Andromeda Collision
Recent simulations suggest that our Galaxy might avoid colliding with the Andromeda Galaxy in the next few billion years, giving it a 50% chance of survival.
The Milky Way and Andromeda are currently approaching each other at a speed of 100 kilometers per second, and scientists previously predicted they would enter a collision course in approximately 4.5 billion years—an outcome that could signal trouble for our Universe.
Earlier studies indicated that our Sun (along with Earth) could end up at the core of a merged galaxy, possibly forming a supermassive black hole, or even being ejected into intergalactic space.
However, a new study published in Nature Astronomy suggests that concerns about the Milky Way’s imminent demise may be overstated. An international team of astrophysicists estimates that the odds of a collision between the two galaxies over the next 10 billion years are around 50%.
“Essentially, it’s a mixed bag,” said Til Sawala, the study’s lead author from the University of Helsinki.
The scientists conducted over 100,000 simulations utilizing recent data from space telescopes.
Sawala noted that a direct collision between the galaxies in the next 5 billion years is “highly unlikely.” The most probable outcome involves the Milky Way and Andromeda passing by each other. In half of the simulations, dark matter may pull them into a future collision, but this would not occur for another 8 billion years—well after our Sun has ceased to shine.
“It’s possible that the Milky Way could be destroyed, but we also cannot rule out that the two galaxies have been orbiting each other for tens of millions of years,” Sawala remarked. “The fate of the Milky Way remains uncertain.”
Sawala indicated that data from the Hubble and Gaia space telescopes, which recently concluded their missions, may enable astrophysicists to provide clearer answers within the next decade.
Despite the looming threat of climate change making Earth uninhabitable in about 1 billion years, Sawala believes there’s a strong emotional connection to understanding the future. “I’d prefer for the Milky Way to avoid a collision with Andromeda, even if it doesn’t affect my life—or my tricuspids,” he quipped.
