💥 Milky Way's collision with Andromeda galaxy called into question

The collision between the Milky Way and Andromeda, long considered inevitable, might ultimately not occur. Recent simulations challenge this prediction, opening new perspectives on our galaxy's fate.

Astronomers previously believed the Milky Way and Andromeda, its closest spiral neighbor, would collide in about 5 billion years. This merger was expected to create a new galaxy nicknamed 'Milkomeda'. However, a recent study published in Nature Astronomy reveals this encounter is no longer so certain.


The research team, led by Til Sawala from the University of Helsinki, used updated data from the Hubble Space Telescope and ESA's Gaia mission. This information enabled more precise simulations of both galaxies' future movements. Results show only a 50% probability of merger within the next 10 billion years.

The simulations also account for gravitational influence from the Large Magellanic Cloud, a dwarf galaxy orbiting the Milky Way. This inclusion significantly alters previous predictions, reducing chances of a head-on collision between the Milky Way and Andromeda to less than 2%.

According to researchers, if both galaxies pass within 500,000 light-years of each other, a merger could still occur. Otherwise, they would continue evolving independently. This uncertainty highlights the importance of future observations to refine models.

Paradoxically, the study suggests the Milky Way has high probability of merging with the Large Magellanic Cloud within the next 2 billion years. This event could further influence our galaxy's trajectory, making any potential encounter with Andromeda even more uncertain.

Upcoming data from Gaia and Hubble should provide clarification on these scenarios. Scientists eagerly await this information to better understand our galaxy's cosmic destiny and that of its neighbors.

What influences galaxies' trajectories?

A galaxy's trajectory is primarily determined by gravitational forces exerted by massive objects around it. This includes other galaxies, galaxy clusters, and even invisible dark matter composing much of the Universe.

Gravitational interactions can alter a galaxy's speed and direction, sometimes significantly. For example, the Large Magellanic Cloud, though much smaller than the Milky Way, has notable impact on its motion.

Computer simulations play key role in understanding these complex dynamics. They allow scientists to predict how galaxies will evolve over billions of years, accounting for multiple factors.

However, these models heavily depend on observational data accuracy. More precise measurements of galaxies' positions and velocities significantly improve prediction reliability.

Why are galaxy mergers important?

Galactic mergers are major events in Universe's evolution. They can trigger new star formation and radically alter involved galaxies' structures.

When two galaxies merge, their stars and gas interact, often without direct collisions due to vast distances between objects. However, gravitational forces can compress gas clouds, promoting star birth.

These events may also lead to elliptical galaxy formation, which differ from spirals like the Milky Way in shape and stellar population. Understanding these processes helps astronomers reconstruct Universe's history.