When Galaxies Merge

[Baddad (Marty)]

When galaxies collide/join.
What is the effect on the planets that are associated with the various stars.
What may happen to the stars themselves?
After all they are separated by distances of light years magnitude.
Does it all become like a giant solar system where planets fly off like asteroids?

What is known about this phenomena to date?

Cheers

[Astro_Bot]

According to what I've read, not much happens on a solar-system scale. There might be a purturbed orbit or two, but only if the system in question is unlucky enough to have another star pass really close by (on an astronomical scale).

Of course, not having actually seen one ....

[Astro_Bot]

Ah, here's the most recent thing I was reading (which has probably been posted before somewhere on the forum, but I haven't looked):

NASA's Hubble Shows Milky Way is Destined for Head-On Collision

[Baddad (Marty)]

Hi Astro-Bot,

Thanks for that link. I had been aware of Andromeda for some time. That video is interesting.
Hard to fathom that the tidal attraction is there and not affecting the solar system much (what may remain of it).

A collision on such a massive scale and yet only the night sky changes character.

Cheers

[ZeroID (Brent)]

It's alright, it's about 2 billion years away so I don't think it will bother us much ...

We are alll stardust anyway ...

[CarlJoseph (Carl)]

Hi Baddad,

Quite a bit is know about galaxy mergers although a lot of it is through computer simulations. Galaxies though do collide and impact each other, and it's not uncommon. Take a look at the Arp Catalog for examples.

Originally Posted by Baddad

What may happen to the stars themselves?
After all they are separated by distances of light years magnitude.
Does it all become like a giant solar system where planets fly off like asteroids?

You're correct, the stars are so far apart in a galaxy that they are very unlikely to collide. When two spiral galaxies collide for example, the stars end up on all sorts of random orbits which resemble a blog of an elliptical galaxy.

There are a few online simulations which you can view and some you can also play with ... Chris Mihos has published some information on his site about this topic (although it's a little out of date now) ... http://burro.cwru.edu/JavaLab/GalCrashWeb/backgrnd.html

There's also this applet which you can use to run your own simulations ... http://burro.cwru.edu/JavaLab/GalCrashWeb/

Enjoy!
Af.