Jun 2, 2025 08:31 PM
(This post was last modified: Jun 2, 2025 08:33 PM by C C.)
https://www.eurekalert.org/news-releases/1085453
INTRO: Scientists from Helsinki, Durham and Toulouse universities used data from NASA’s Hubble and the European Space Agency’s Gaia space telescopes to simulate how the Milky Way and Andromeda will evolve over the next 10 billion years. The two galaxies are currently heading towards each other at a speed of about 100 kilometres per second.
A collision would be devastating for both galaxies which would be destroyed, leaving behind a spheroidal pile of stars known as an elliptical galaxy. The team ran 100,000 simulations of both galaxies based on the latest observational data.
This included the effect of the Milky Way’s most massive satellite, the Large Magellanic Cloud (LMC), and importantly, for the first time, including uncertainties in the observables. They found only a 2% probability that the galaxies will collide in the next five billion years, contrary to the previous belief that a collision – and the demise of the Milky Way - was a certainty within that timeframe.
In just over half of the simulated scenarios, the Milky Way and Andromeda experience at least one close encounter, before losing enough orbital energy to eventually collide and merge - but in eight to ten billion years’ time, not five.
On that timescale the Sun will have already burnt itself out. In most other cases, the two galaxies pass at such a large distance that they continue to evolve largely unperturbed for a very long time.
The study has been published in the journal Nature Astronomy...... (MORE - details, no ads)
INTRO: Scientists from Helsinki, Durham and Toulouse universities used data from NASA’s Hubble and the European Space Agency’s Gaia space telescopes to simulate how the Milky Way and Andromeda will evolve over the next 10 billion years. The two galaxies are currently heading towards each other at a speed of about 100 kilometres per second.
A collision would be devastating for both galaxies which would be destroyed, leaving behind a spheroidal pile of stars known as an elliptical galaxy. The team ran 100,000 simulations of both galaxies based on the latest observational data.
This included the effect of the Milky Way’s most massive satellite, the Large Magellanic Cloud (LMC), and importantly, for the first time, including uncertainties in the observables. They found only a 2% probability that the galaxies will collide in the next five billion years, contrary to the previous belief that a collision – and the demise of the Milky Way - was a certainty within that timeframe.
In just over half of the simulated scenarios, the Milky Way and Andromeda experience at least one close encounter, before losing enough orbital energy to eventually collide and merge - but in eight to ten billion years’ time, not five.
On that timescale the Sun will have already burnt itself out. In most other cases, the two galaxies pass at such a large distance that they continue to evolve largely unperturbed for a very long time.
The study has been published in the journal Nature Astronomy...... (MORE - details, no ads)