Novos calculations based on precise measurements from the Gaia satellite raise the probability of merger between Via Láctea and Andrômeda to 90% in the next 10 billion years. The study, published in March 2026, incorporates the most refined proper motions of stars in the neighboring galaxy, significantly reducing the uncertainties that hung over the fate of the two cosmic giants. The dark matter halos of galaxies, each containing approximately one trillion solar masses, are already in gravitational contact. The current relative speed between them reaches 110 kilometers per second, maintaining a continuous approach trajectory.
Refined Dados from Gaia transforms astronomical predictions
Pesquisadores performed 10,000 future trajectory simulations to map the behavior of the local group of galaxies, including Via Láctea, Andrômeda, M33 and Grande Nuvem of Magalhães. The calculations incorporate the most precise proper motions available for stars in Andrômeda, obtained from refined observations from the European satellite. The predicted average time for fusion reaches 6.5 billion years, with a margin of uncertainty between 5 and 7.8 billion years. Essa approach contrasts with analyzes from 2025 that estimated only a 50% chance of merger, considering larger uncertainties in the masses and positions of the galaxies.
The Gaia measurements reduced some of the doubt that hung over the inevitable meeting. The proper motions now available, with uncertainties of less than 2 microarcseconds per year, have allowed astronomers to largely restore the classical view of the fate of the two galaxies. Frontal and lateral projections reveal patterns of orbits with varying probability density over time.
Processo merger creates Milkomeda without direct collision between stars
- Vast interstellar space allows stellar systems to intertwine without direct physical clashes.
- The spiral disks of the two galaxies distort and mix, forming a giant elliptical structure.
- The resulting galaxy, named Milkomeda, will have approximately twice the stellar and dark matter mass as today’s Via Láctea.
- Sol will remain active during the initial phases of the merger, with a remaining life expectancy of about 7.6 billion years.
Computer simulations show that the process involves the shuffling of the stellar disks of the two spirals without collisions between individual celestial bodies. The immense distances that separate stars within galaxies ensure that no direct collisions occur. A hypothetical observer at Terra would be able to see the two galaxies approaching each other as stars fill the night sky in ever-changing configurations.
Influência of smaller galaxies complicates local group dynamics
Grande Nuvem of Magalhães and M33 play secondary but relevant roles in the full simulations. The perpendicular orbit of Grande Nuvem and Magalhães with respect to the main plane of the two giants introduces additional uncertainties in the projections. Mesmo thus, the inclusion of M33 in the simulations tends to increase the overall chance of merger between Via Láctea and Andrômeda. Simulated trajectories for 100 randomly selected paths demonstrate significant variations in the separation between galaxy centers over time.
The lines representing the orbits highlight the probability density at different positions over billions of years. In about 90% of the analyzed trajectories, the merger occurs within a 10 billion year interval. The median time of 6.5 billion years concentrates most of the likely occurrences, reflecting current limitations in accurate measurements of distant stellar movements.
Isolated Futuro awaits Milkomeda in expanding universe
Após the merger complete, the rapidly expanding universe will leave Milkomeda in an increasingly isolated environment. Dentro for a hundred billion years, the giant galaxy will be surrounded by regions of cosmic vacuum. Hypervelocity Estrelass ejected during the process may serve as indirect evidence of universal expansion even on extremely long time scales. The complete merger process spans billions of years, with multiple passes and gravitational interactions before final stabilization in an elliptical galaxy.
Durante During this period, the night sky would undergo visible transformations on geological and astronomical timescales. The stars would redistribute themselves into new orbital patterns around the combined center. The dark matter halos, which are already touching each other, begin the process of large-scale gravitational interaction. The luminous cores, rich in stars, follow trajectories that lead to the progressive shuffling of the disks until the formation of the final elliptical structure.