Milkyway & Andromeda May Not Merge After All

[Economy 53,112]

https://www.nature.com/articles/s41550-025-02563-1

 

I saw a video on this recently and found it fascinating. For a long time it was considered nearly garanteed than in a few billion years the Milkyway & Andromeda galaxy would colide and merge into 1 larger Galaxy (Milkomeda)

 

However, new estimates suggest that despite the fact that Andromeda and Milkyway are by far the 2 largest Galaxies in local group, gravitational influences of smaller galaxies may have been under estimated

 

The 3rd and 4th largest galaxies in particular (the Large Magelenic Cloud and m33) may influence the tragectory in a way that the two giants will instead just graze eachother but not merge (at least not anyway)

 

Some estimates in fact suggest a direct merge as innitially thought in just a few billion years may be as low as a 2% probability

 

However if they graze eachother they may slow down speed and start orbiting inna dance. There is about a 50% chance that although a direct merge may be missed innitially, an eventual merge will still occur within 10 billion years

 

There is about a 50% chance that we wont merge at at all within next 10 billion years.

 

In the meantime Andromeda and Milkyway will continue to eat other galaxies in local group of which currently about 60 are known

[FfFfFfFF 58,766]

They said 

[Magneto 13,587]

We did it, kids

[Decodekid 31,004]

Is this a thread to Rita Ora? 

[elegidadedios 5,101]

The dead dance cancelled i guess

[Lucas 31,538]

I had to google what happens when galaxies merge since my tiny human brain couldn't really imagine anything...

Turns out that stars rarely ever collide since there is just so much empty space, but that this event leads to the creation of a huge amount of new stars, from shockwaves causing huge compression on gas and dust clouds  I thought everything would be destroyed but it actually leads to creation

[FfFfFfFF 58,766]

54 minutes ago, Lucas said:

I had to google what happens when galaxies merge since my tiny human brain couldn't really imagine anything...

Turns out that stars rarely ever collide since there is just so much empty space, but that this event leads to the creation of a huge amount of new stars, from shockwaves causing huge compression on gas and dust clouds  I thought everything would be destroyed but it actually leads to creation

This confirms parts of the Indian philosophy/cosmology, as it notices there is an intimate link between creation and destruction. 

[Economy 53,112]

3 hours ago, Lucas said:

I had to google what happens when galaxies merge since my tiny human brain couldn't really imagine anything...

Turns out that stars rarely ever collide since there is just so much empty space, but that this event leads to the creation of a huge amount of new stars, from shockwaves causing huge compression on gas and dust clouds  I thought everything would be destroyed but it actually leads to creation

Yup correct. The space between stars on average is equivaent to 2 grains of sand 5 miles apart for reference. The chances of any direct colision even with gravitational influences are extremely low

 

That being said i did read in some cases the gravitational disruption can throw some stable orbits off balance in a few parts of the galaxy. Not many, but a few if ur unlucky to be in a bad spot. The denser galactic centres also have a slightly higher risk of messy events. So theres that. So destruction isnt always 0. But it is low overall and it does usually lead to lots of star formation its believed

[Guest]

Nobody cares about these flops anymore 

[Ilia Malinin 3,091]

7 hours ago, Economy said:

For a long time it was considered nearly garanteed than in a few billion years the Milkyway & Andromeda galaxy would colide and merge into 1 larger Galaxy (Milkomeda)

you see, hearing this as a child would've sent me into the same spiral as "the sun is going to explode in 1 billion years."  i won't even be alive and it would've still had me panicked.  my anxiety has been here for DECADES, i fear.

[Economy 53,112]

Just now, elsamars said:

Nobody cares about these flops anymore 

But out of the 60 galaxies Andromeda and Milkyway are the biggest

 

From largest to smallest:

 

1. Andromeda - Taylor Swift

2. Milkyway - Lady Gaga

3. M33 - Rita Ora

4 Large Megelenic Cloud- Katy Perry

5 to 60- underground artists

 

This is like Lady Gaga and Taylor Swift cancelling their wedding in front of their smaller peers

[SidewalkUnicorn 285]

They had a falling out and this is none of our business y’all.

[Madame Goo Goo 4,146]

Can someone ELI5 how we know any of this lmao

[Economy 53,112]

1 hour ago, Madame Goo Goo said:

Can someone ELI5 how we know any of this lmao

I mean they dont know anything for sure thats why they speak on probabilities...

 

Ever heard of the 3 body problem? Once theres more than 2 objects in an orbit with any meaningful gravitational impact the math to calculate the orbit for any length of time becomes extremely difficult, in fact impossible...

 

It works in a solar system like ours because the Sun is over 99% of the Solar Systems mass with Jupiter as a second body by itself being the majority of the rest, so all the other planets abd asteroids by themselves have such a tiny impact that we can still predict orbits with a pretty high degree of acuracy

 

But in this case we have 2 giant galaxies (Andromeda & Milkyway), another 2 decent sized Galaxies (M33 & LMC) so that brings the total up to 4 bodies of meaningful impact, plus the dwarf galaxies that although small compared to the main galaxies, they still have more impact than say our planets in solar system

 

So they can only calculate likely tragectories with probabilities. The direction stuff is moving in now doesnt mean its the same direction well be moving still in a few million years

 

If we kept going in the same direction the galaxies would in fact merge, but they realized this assumption is far too simplistic and underestimates the amount of tug and pull the dozens of other galaxies have on us (especially the M33 and MLC galaxies which are 30% to 40% as massive as the milkyway so the influence isnt small)