Astronomers Predict Titanic Collision: Milky Way vs. Andromeda

[BridgeTheGap]

May 31, 2012: NASA astronomers say they can now predict with certainty the next major cosmic event to affect our galaxy, sun, and solar system: the titanic collision of our Milky Way galaxy with the neighboring Andromeda galaxy.

The Milky Way is destined to get a major makeover during the encounter, which is predicted to happen four billion years from now. It is likely the sun will be flung into a new region of our galaxy, but our Earth and solar system are in no danger of being destroyed.

"After nearly a century of speculation about the future destiny of Andromeda and our Milky Way, we at last have a clear picture of how events will unfold over the coming billions of years," says Sangmo Tony Sohn of the Space Telescope Science Institute (STScI) in Baltimore.

"Our findings are statistically consistent with a head-on collision between the Andromeda galaxy and our Milky Way galaxy," adds Roeland van der Marel of the STScI.

http://science.nasa.gov/science-news/science-at-nasa/2012/31may_andromeda/

[trotsky]

1. Can't wait to watch! n/t

[Wabbajack_]

2. To

To say they can predict with "certainty" what will happen billions of years from now is beyond silly.

[ProdigalJunkMail]

3. so i guess all data extrapolation is out?

it is not silly at all. there is simple movement of the galaxies...measured. there are laws and rules to physics...observed. put those two together and WHAMO! you can reasonably predict the future.

sP

[VWolf]

9. Time scales are relative

For gravitation, at astronomical scales, a few billion years is not all that long.

[Tanelorn]

4. Could we perhaps get the same scientists to predict what might happen to the climatein say the next

50 to 100 years

[longship]

5. Unfortunately the Navier-Stokes equations are difficult to solve

Unlike Newtonian mechanics, which work quite well for predicting two galaxies paths in the future.

Weather and climate are chaotic which is why N-S cannot be solved accurately in the far future.

The only thing climatologists can do is model the systems the best they can.

[VWolf]

8. Isn't gravitation also chaotic for anything more than 2 bodies?

I seem to remember reading that once.

I'm guessing that the model they're using treats each galaxy as a single body (or some sort of extended body), and they're only looking at gross behavior over time.

[longship]

12. Yes, correct, however...

1. The two galaxies at 2+ million light years distance can be considered as single points. As they get closer it gets more complex. However...

2. The gravitation equation is easy to solve and more easily modeled in the impossible three-body situation. The Navier-Stokes equation is always complex because turbulence is always chaotic.

Even though these are true, the interaction of two galaxies colliding would take a super computer, just like climate. But the for one the mathematics is simpler (if one ignores relativity).

[CanonRay]

6. That's a little past my "Sell by" date

[ProdigalJunkMail]

7. for most of us, i think :-) n/t

[Th1onein]

10. Nope, not for us reincarnationists

eom

[ProdigalJunkMail]

11. or time travelers... n/t

[Neoplebe]

13. And we're busy fighting over a rock

Kind of puts our petty squabbles in perspective, doesn't it?

[Skinner]

14. Yes, it does.

Welcome to DU.

[pokerfan]

15. Download the hi-res images here

Yeah, it's 108MB but what can you do. Each image is 3600x2025 pixels.

http://planetary.s3.amazonaws.com/assets/images/universe/andromeda_collision.zip

1. Present day.
   
2. In 2 billion years the disk of the approaching Andromeda galaxy is noticeably larger.
   
3. In 3.75 billion years Andromeda fills the field of view.
   
4. In 3.85 billion years the sky is ablaze with new star formation.
   
5. In 3.9 billion years, star formation continues.
   
6. In 4 billion years Andromeda is tidally stretched and the Milky Way becomes warped.
   
7. In 5.1 billion years the cores of the Milky Way and Andromeda appear as a pair of bright lobes.
   
8. In 7 billion years the merged galaxies form a huge elliptical galaxy, its bright core dominating the nighttime sky.

[BridgeTheGap]

16. My money is on the Milky Way in this bout. Andromeda is totally out-classed! n.t