will our Milky means galaxy really collide v the Andromeda Galaxy? as soon as will it happen, and also how does our Galaxy compare to the Andromeda Galaxy?


Our galaxy is top top a collision course. In approximately 4.5 billion years’ time the Milky means will smash into the swiftly approaching Andromeda Galaxy, and also astronomers room still attempting to predict what it will be like as soon as the two galaxies collide.

You are watching: How long until andromeda collides with milky way

That a collision between our galaxy and also the Andromeda Galaxy is inevitable has actually been known for a little while. It’s been clear from measurements of the Doppler shift of that is spectral lines the Andromeda was approaching, but such measurements deserve to only call you about the motion directly towards or away from the observer.

Working the end if us were in because that a direct hit or a close to miss as such required mindful study of the activity of Andromeda’s satellite galaxies, and also they expose Andromeda’s trajectory renders collision inevitable.


A pair the colliding galaxies nicknamed ‘The Mice’, recorded by the Hubble room Telescope. Once galaxies merge, stars are extremely unlikely come collide, due to the large distances in between them. Credit: NASA, Holland Ford (JHU), the ACS scientific research Team and ESA
Plugging this information on the relative velocities, estimates of the masses of the galaxies and details of your structure into their model, the writer of one interesting paper on this galactic collision have actually watched the occasion unfold.

Though the details rely to some degree on galactic structure and in specific on presumptions we make around the haloes the dark matter that save the visible discs the the Milky method and Andromeda, the general snapshot is clear.

After a spectacular series of close overcome lasting billions of years – and also which will distort the framework of both galaxies – a last merger the the Andromeda Galaxy and also the Milky way galaxy will occur around 10 billion year from now.

What will occur when Andromeda and the Milky means collide?

The an outcome of the collision between Andromeda and also the Milky means will it is in a new, larger galaxy, but rather 보다 being a spiral favor its forebears, this brand-new system ends up together a large elliptical.

The authors of the document in question have named this new galaxy ‘Milkdromeda’. There’s something about this name that really bugs me. Surely we require something grander sounding? If you deserve to think of a better name, let us know by emailing contactus

For the very first time, the simulation contains details that what wake up to the supermassive black color holes that lurk in ~ both galaxy centres. The pair will finish up creating a binary at the love of the new, bigger galaxy.


Left: elliptical galaxy NGC 4621. Right: Spiral galaxy NGC 1015. Credit: ESA/Hubble & NASA, P. Cote / ESA/Hubble & NASA, A. Riess (STScl/JHU)
This binary isn’t stable, though. Communication with your surroundings way that the pair will spiral inwards, create gravitational waves together they do so.

In only about 17 million years, the two will be close sufficient that the loss of energy through this gravitational tide drives a final inward spiral and merger.

The gravitational wave signal of an event like this can not be detect by LIGO (the Laser Interferometer Gravitational-Wave Observatory), i m sorry is sensitive only to the merger of lower mass black holes and neutron stars.


an artist’s impression of 2 binary black color holes in orbit about each other. Credit: The SXS (Simulating too much Spacetimes)
In the future, the simulations suggest that ESA’s LISA (Laser Interferometer an are Antenna) mission have to observe together mergers the end to an approximate redshift of 2 – therefore in a te or so we may have the ability to see how predictions that the fate of the Milky Way’s black hole match up to comparable events elsewhere.

The file ends ~ above a melancholic note: the authors’ estimate of 10 billion years for the closing to reach its finish is longer than in previous studies, but way that the sunlight will no live long enough to find a home in the brand-new galaxy.

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We’ll need to enjoy the results of simulations instead.

Andromeda vs the Milky Way

Milky Way


The Milky means galaxy sets over Fajada Mesa in ~ Chaco Canyon, brand-new Mexico. Credit: Eric Lowenbach / Getty Images
Size 100,000 lightyears acrossNumber of stars 100 exchange rate starsType that galaxy Spiral galaxyAge 13.6 exchange rate years

Andromeda Galaxy