It's headed right for us!

[pokerfan]

in four billion years....

The galaxy we live in, the Milky Way, is a large spiral galaxy that lives in a small cluster of other galaxies called the Local Group. The other big member is the Andromeda galaxy, located about 2.5 million light years away. That’s a long way off, but we’ve known for a long time that Andromeda is heading more or less toward us at a speed of roughly 100 km/sec (60 miles/second).

The question is, is it headed directly at us, or does it have some "sideways" motion and will miss us? New results announced today by astronomers using Hubble show that — gulp! — Andromeda is headed right down our throats!

This is a pretty cool result. They used Hubble to look at stars in Andromeda’s halo, the extended fuzzy region outside the main body of the galaxy. By very carefully measuring the positions of the stars over seven years, they could directly measure the motion of those stars. Extrapolating that into the future has allowed the motion of the Andromeda galaxy itself to be determined for the first time.

http://blogs.discovermagazine.com/badastronomy/2012/05/31/hold-on-tight-in-4-billion-years-were-due-for-a-galactic-collision/

[DrDan]

1. oh boy . . . stock up on the duct tape and water

[ladjf]

2. No need to worry. The Sun will have vaporized Earth long before that. About 1 billion years it will

be too hot for life to exist. 5.6 billion years to be evaporated.

[SoutherDem]

3. The Republican will blame this too on Obama

[edcantor]

6. And Obama and science is surely to blame!

If we just believed in God, this would never have come up.

But those damned scientists and Obama, those naturalists. and those secularists. We must get back to Jesus and God and being born again, so we can avoid any more mention of science in our lives.

Obama surely created all this, and think what he could do if he were re-elected.

[Ron Obvious]

4. Won't galaxies mostly pass right through each other?

Since there's so much empty space even within a galaxy, I'm thinking 2 galaxies would mostly just pass right through each other. I suppose there could be some orbital disruptions because of gravitational pull, but I'm guessing there will be few actual collisions.

[longship]

5. Absolutely true!

But the matter in both get mighty stirred up. That means that both spirals twist and turn as gravity effectively pull them into decidedly non-spiral configurations.

There are animations online showing computer models of such interactions.

[pokerfan]

7. Yeah, direct star to star collisions would be unlikely

It's more of the galaxy as a whole...

[jimlup]

8. But the star formation set off by the event should be spectacular!

There will be a whole generation of stars born in this event. Kinda seems like intergalactic sex or something.