New computer simulations have revealed that our Milky Way galaxy might avoid a catastrophic collision with the neighboring Andromeda galaxy, contrary to previous predictions of a massive galactic smash-up.
The Milky Way and Andromeda are hurtling towards each other at a staggering 100 kilometers per second. Scientists had long expected that in about 4.5 billion years, the two galaxies would collide, potentially resulting in the destruction of our galactic home.
However, an international team of astrophysicists has found that there’s only about a 50% chance of such a collision occurring in the next 10 billion years. “It’s basically a coin flip,” said Till Sawala, lead author of the study from the University of Helsinki.
Using over 100,000 computer simulations and new observations from space telescopes, the researchers discovered that a merger in the next five billion years is “extremely unlikely.” Instead, it’s more probable that the galaxies will pass close to each other—within just under 500,000 light-years—without colliding.
In only half of the simulations did dark matter eventually cause the Milky Way and Andromeda to merge, but this would take around eight billion years. By then, our Sun would have already aged beyond its life-sustaining phase.
“So it could be that our galaxy will end up destroyed,” Sawala explained. “But it’s also possible that our galaxy and Andromeda will orbit one another for tens of billions of years—we just don’t know.”
The fate of our galaxy remains uncertain. Future data from space telescopes like Gaia and Hubble could provide more definitive answers within the next decade.
As for life on Earth, the Sun is expected to make our planet inhospitable in about a billion years. While these galactic events may not affect us directly, they certainly inspire wonder about our place in the universe.
