When our galaxy smashes into Andromeda what happens to the sun & our solar system?

Question

Bothe galaxies are 2.6 million light-years apart now and will emerge as one a few billion years from now. But, when it does happen, what do you think will happen?

Answer 1

The first sideswipe will occur less than 2 billion years from now. During that first interaction, there’s a 12% chance that the Solar System might get ejected from the disk of the Milky Way, and spun out into the tidal tail of material that will stream out from the Milky Way. And there’s a remote chance, less than 3%, that the Sun will jump ship, joining up with Andromeda, and leaving the Milky Way entirely.

Since the Sun and the Earth will still be around, future astronomers could witness the collision in all its glory. Since the Sun will be steadily increasing its output of radiation, life might not be able to survive on our planet if engineers can’t figure out a way to keep the Earth moving away from the Sun.

Then the galaxies will come back together for another swipe, and then another, and eventually settle down into a gigantic swarm of stars buzzing around a common center of gravity. Currently quiet, the twin supermassive black holes may flare up, becoming active galactic nuclei, feasting on the torrent of new material that was unlucky to enter their feeding zones. Colliding clouds of gas and dust will flare up in furious regions of star formation.

In all likelihood, these interactions will push the Sun out into the new galaxy’s outer halo, pushing us at least 100,000 light years from the centre, and safely way from those twin black holes.

And 7 billion years from now, when our Sun is in the last stages of life - a red giant - and our Earth is a burned cinder, Milkomeda will have formed.

(At least, that’s what Cox and Loeb are calling it. I coined Milkdromeda in an episode of Astronomy Cast.)

This future galaxy will be a massive, elliptical galaxy, losing any remnant of its familiar spiral arms. The furious star formation will settle down, and this new galaxy will live out its remaining years, slowly using up its remaining raw stellar material.

100 billion years from now, all galaxies not bound to the Local Group will recede from vision - now traveling away from us faster than the speed of light. The concept of extragalactic astronomy will end, and Milkomeda will account for the entire visible Universe.

Answer 2

Very little would happen. Look at it this way, the nearest star is 4.35 lightyears away. Galaxies are 99.99999% empty space. So two galaxies collide. The biggest effect will be that nebulas in each, which tend to be a few lightyears across, will collide, probably setting off the formation of some new stars. But existing stars will happily drift on by. Maybe in two colliding galaxies there might be a couple close approaches, which would disrupt a couple planetary systems. With over two hundred billion stars in our galaxy, and about 350 billion in Andromeda, the odds aren't too bad.

Answer 3

I believe that the sun will engulf the earth before that event. If not we would absorb each other during a collision and within 20-30 million years a Super Galaxy would form with 1 giant Black Hole. There are many examples of this in space already.

MK

Answer 4

nothing

imagine a hand full of sand thrown in the air
imagine it could fly 10 meters and at the other side a friend throws another hand full of sand
just imagine how many sand grains colliding another.......
hard to think, isn't it?
the grains are too separated one from the other, and now...
add speed, the galaxies move one into another at speeds of 30 km sec, and the suns are at distances of ligth years
what's the chance that one will meet another at a certain point at the SAME time?!??!!
only in earth two planes collide into another , because the pilots are stupids, but the stars arent.
one or some , maybe
but our sun? oohhh, not a chance!!

Answer 5

actually this will be amazing for us! what will happen is that the galaxies will collide/go through eachother, no collusions or anything! galaxies do that ALL the time... a star will pass by the other star its sun will pass by our sun..and the planets might pass other planets and new planets might even form, i think there is also a possibility that we might become a large galaxy (both combined)

Answer 6

Think of it not as a collision but a merger since stars are so far apart they don't really collide. It will just take its place in what will probably be an iregular gallaxy.

Answer 7

dont worry, mankind wont last for that long. so lives on earth will probably be long gone in a few million years, not even billion. you and i wont exist anyway.

Answer 8

We wil not last that long . It will take billions of years .

Answer 9

well it won't and if it did, nothing would happen. there is too much empty space.