New research suggests Milky Way may avoid catastrophic collision with Andromeda galaxy
By isabelle // 2025-06-03
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  • Astronomers now estimate a 50-50 chance the Milky Way will avoid colliding with Andromeda, revising earlier near-certain predictions.
  • New data from Hubble and Gaia telescopes show smaller galaxies may alter the Milky Way and Andromeda’s paths, preventing a direct impact.
  • Earlier models suggested a merger in ~4 billion years, but updated simulations show it could be delayed or avoided entirely.
  • If a collision happens, it may occur in ~8 billion years, far later than previously thought, giving more time for cosmic evolution.
  • Earth will become uninhabitable long before any galactic collision due to the Sun’s expansion in ~5 billion years.
For decades, astronomers warned that the Milky Way was on an unstoppable collision course with the Andromeda galaxy in a catastrophic merger that would reshape our cosmic neighborhood in roughly 4 billion years. But groundbreaking new research suggests this doomsday scenario may never happen. According to data from the Hubble and Gaia space telescopes, the Milky Way now has a 50-50 chance of avoiding a direct collision with Andromeda thanks to gravitational influences from smaller neighboring galaxies. The findings, published in recent astrophysical studies, dramatically revise earlier predictions and offer a potential escape from the so-called "Milkomeda" fate. Scientists have long assumed that the Milky Way and Andromeda, the two largest galaxies in the Local Group, were destined to collide due to their mutual gravitational pull. Previous estimates placed the likelihood of a merger at near certainty, with projections suggesting a chaotic cosmic dance beginning in about 4 billion years. But the latest models, which incorporate precise measurements of galactic motions, reveal that smaller satellite galaxies could alter this trajectory, potentially steering the Milky Way and Andromeda away from a direct impact.

Revised galactic trajectories

The key to this revised forecast lies in the gravitational influence of dwarf galaxies orbiting both the Milky Way and Andromeda. These smaller celestial bodies, once considered negligible in the grand scheme of galactic dynamics, may exert enough force to nudge the two giants off their collision course. Researchers used data from the European Space Agency’s Gaia mission, which maps the positions and movements of billions of stars, combined with Hubble’s deep-space observations, to simulate multiple possible outcomes. "The Local Group is a dynamic system where even small galaxies can have a significant impact over billions of years," explained one researcher involved in the study. While the exact outcome remains uncertain, the models suggest a wide range of possibilities — from a near-miss to a delayed, less violent encounter. If a collision does occur, it likely won’t happen for at least 8 billion years, giving future civilizations (or whatever may evolve from humanity) far more time to prepare or evacuate.

A cosmic game of gravitational pinball

The revised predictions highlight the complexity of galactic interactions, where even minor players can alter the fate of much larger systems. Imagine a game of cosmic pinball, where the Milky Way and Andromeda are the main targets, but smaller galaxies act as bumpers, subtly redirecting their paths. This intricate interplay challenges the long-held assumption that the merger was inevitable. One critical factor is the relative speed of Andromeda’s approach. Earlier estimates suggested it was moving directly toward the Milky Way at approximately 110 kilometers per second. However, updated measurements indicate its trajectory may be more tangential, reducing the likelihood of a head-on collision. Instead, the two galaxies might engage in a series of close passes, gradually spiraling closer over eons — or they could drift apart entirely.

What this means for Earth’s distant future

While the revised timeline offers a glimmer of hope for the Milky Way’s survival, Earth’s fate remains bleak in the grand cosmic scheme. Long before any potential galactic collision, our Sun will have exhausted its fuel, expanding into a red giant and likely rendering our planet uninhabitable in about 5 billion years. Still, the new findings reshape our understanding of the universe’s evolution and the forces governing its largest structures.

A universe of possibilities

The Milky Way’s fate is no longer written in stone — or rather, in stars. While the chance of a collision with Andromeda remains, the odds have shifted dramatically, offering a 50% probability that our galaxy will avoid a catastrophic merger. Sources for this article include: LiveScience.com Space.com NationalGeographic.com
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