The Coming Titanic Milky Way-Andromeda-Triangulum Galaxy Mashup!

 

            


NASA astronomers announced Thursday 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.

"Our findings are statistically consistent with a head-on collision between the Andromeda galaxy and our Milky Way galaxy," said Roeland van der Marel of the Space Telescope Science Institute (STScI) in Baltimore.

The solution came through painstaking NASA Hubble Space Telescope measurements of the motion of Andromeda, which also is known as M31. The galaxy is now 2.5 million light-years away, but it is inexorably falling toward the Milky Way under the mutual pull of gravity between the two galaxies and the invisible dark matter that surrounds them both.

"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," said Sangmo Tony Sohn of STScI.

The scenario is like a baseball batter watching an oncoming fastball. Although Andromeda is approaching us more than 2,000 times faster, it will take 4 billion years before the strike.Computer simulations derived from Hubble's data show that it will take an additional two billion years after the encounter for the interacting galaxies to completely merge under the tug of gravity and reshape into a single elliptical galaxy similar to the kind commonly seen in the local universe.

Although the galaxies will plow into each other, stars inside each galaxy are so far apart that they will not collide with other stars during the encounter. However, the stars will be thrown into different orbits around the new galactic center. Simulations show that our solar system will probably be tossed much farther from the galactic core than it is today.

To make matters more complicated, M31's small companion, the Triangulum galaxy, M33, will join in the collision and perhaps later merge with the M31/Milky Way pair. There is a small chance that M33 will hit the Milky Way first.

The universe is expanding and accelerating, and collisions between galaxies in close proximity to each other still happen because they are bound by the gravity of the dark matter surrounding them. The Hubble Space Telescope's deep views of the universe show such encounters between galaxies were more common in the past when the universe was smaller.A century ago astronomers did not realize that M31 was a separate galaxy far beyond the stars of the Milky Way. Edwin Hubble measured its vast distance by uncovering a variable star that served as a "milepost marker."

Hubble went on to discover the expanding universe where galaxies are rushing away from us, but it has long been known that M31 is moving toward the Milky Way at about 250,000 miles per hour. That is fast enough to travel from here to the moon in one hour. The measurement was made using the Doppler effect, which is a change in frequency and wavelength of waves produced by a moving source relative to an observer, to measure how starlight in the galaxy has been compressed by Andromeda's motion toward us.

Previously, it was unknown whether the far-future encounter will be a miss, glancing blow, or head-on smashup. This depends on M31’s tangential motion. Until now, astronomers had not been able to measure M31's sideways motion in the sky, despite attempts dating back more than a century. The Hubble Space Telescope team, led by van der Marel, conducted extraordinarily precise observations of the sideways motion of M31 that remove any doubt that it is destined to collide and merge with the Milky Way.

"This was accomplished by repeatedly observing select regions of the galaxy over a five- to seven-year period," said Jay Anderson of STScI.

"In the worst-case-scenario simulation, M31 slams into the Milky Way head-on and the stars are all scattered into different orbits," said Gurtina Besla of Columbia University in New York, N.Y. "The stellar populations of both galaxies are jostled, and the Milky Way loses its flattened pancake shape with most of the stars on nearly circular orbits. The galaxies' cores merge, and the stars settle into randomized orbits to create an elliptical-shaped galaxy."

The space shuttle servicing missions to Hubble upgraded it with ever more-powerful cameras, which have given astronomers a long-enough time baseline to make the critical measurements needed to nail down M31's motion. The Hubble observations and the consequences of the merger are reported in three papers that will appear in an upcoming issue of the Astrophysical Journal.

In 2011 astronomers started building an atlas of galactic 'train wrecks' from past and the future -- "A first step in reading the story of how galaxies form, grow, and evolve," according to Lauranne Lanz of the Harvard-Smithsonian Center for Astrophysics (CfA).

In general, galaxy collisions spark star formation. However, some interacting galaxies produce fewer new stars than others. Lanz and her colleagues want to figure out what differences in physical processes cause these varying outcomes. Their findings will also help guide computer simulations of galaxy collisions.

"We're working with the theorists to give our understanding a reality check," said Lanz. "Our understanding will really be tested in five billion years, when the Milky Way experiences its own collision."

Andromeda, a spiral galaxy approximately 2.5 million light-years away in the constellation Andromeda is the nearest spiral galaxy to our own, the Milky Way. Andromeda and the Milky Way are approaching one another at a speed of 100 to 140 kilometers per second (62–87 miles/sec). 

Andromeda, home to the evil Kelvans in an early Star Trek episode, was believed to be the largest galaxy of the Local Group of galaxies, which consists of the Andromeda Galaxy, the Milky Way Galaxy, and the Triangulum Galaxy, and about 30 other smaller galaxies. But scientists now believe that the Milky Way contains more dark matter and may be the most massive in the grouping. 

However, recent observations by the Spitzer Space Telescope revealed that Andromeda contains one trillion stars, greatly exceeding the four billion stars in our own galaxy. 

 

          


The Daily Galaxy via Harvard-Smithsonian Center for Astrophysics

The Daily Galaxy via JPL/NASA

Image credit: NASA; ESA; A. Feild and R. van der Marel, STScI

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Comments

[ophu]

What's going to be hard to stomach is seeing people on street corners holding "The end of the galaxy is coming!" signs for the next four billion years.

[Joe savitzky]

Time enough to stock up on bottled water and AA batteries

[smile]

Interesting findings and facts about our mysterious universe, there is so much to explore there.

[Ivar Nielsen]

THE DARK AGE OF ASTRONOMY; COSMOLOGY AND ASTROPHYSICS

1) Astrophysicists and cosmologists invented “dark matter” in order to - supposedly - explain the galactic rotation anomaly that contradicts the laws of celestial orbiting around a gravity centre.

2) They invented “dark energy” to - supposedly – explain the “supposedly expansion of the universe” where everything – supposedly – moves away from everything.

Quote: “The galaxy is now 2.5 million light-years away, but it is inexorably falling toward the Milky Way under the mutual pull of gravity between the two galaxies and the invisible dark matter that surrounds them both”.

AD: Now they come up with a theory/measurement where 2 galaxies – supposedly - attract each other from a distance over 2.5 million light-years away (!?). In spite of the invented “dark matter” that – supposedly –otherwise should hold the galaxies in their individual position as with the stars in our galaxy, and in spite of the movement of the – supposedly - expanding universe via “dark energy”.

- It seems to me that our days cosmological scholars uses the cosmological terms and ideas very selectively, depending of what they actually want to show or “prove” and it doesn´t matter for them if their changing explanations fit to the occasion are very contradictive in the big and overall cosmological picture, when held together.

To me it also seems that the measurement of the Milky Way and the Andromeda galaxy is a grave misinterpretation of the cosmic movements, combined with misunderstood “laws of gravity”, and nothing else. These 2 galaxies are moving around in larger separate 3D spherical circuits and therefore all kind of angular and distance measurements can show up in the long run.

And as long as the explanations contradicts themselves as noted above, no one should really take this or similar articles for anything else than for just to keep the funding coming and to keep their jobs.

- A new age of a modern cosmology could really emerge from biology. If studying the sperm fertilization of an egg-cell, and watching the bio-electric and bio-magnetic meiosis and mitosis and see how the cell divides in this 3D spherical circuit and cyclic movement, this knowledge can be recognized in all movements in the Universe as the most natural and universal movement of formation.

Natural Philosopher

[Pete]

Ivar this just shows how little we know about our universe.

[Matt Rhodes]

In 4 billion years the Sun will be in it's red giant phase - so the Earth is endangered regardless!

[MandoZink]

Hey Ivar Nielsen. Those of us who are very familiar with how the astronomers and physicists make observations and determine these things can easily see that you are very lacking in astronomical concepts. You could study a bit more (a LOT more actually), and truly understand what's going on in our galactic neighborhood.

It is fairly easy to imagine that if you lived during the the period of Copernicus, Galileo and Kepler, you would be one of the guys wanting to imprison or execute those early astronomers for their heliocentric views.

If I don't understand a science concept, I don't auto-deny it, I get more educated. Try it. It's way better to comprehend something than to look stupid to those who do understand.

[MandoDick]

MandoZink... you look like the fool here not the other guy.

He made very clear and logical points where you just told him he was wrong....

you seem to have the mind set of a little boy.

[smartypants]

MandoZink
Its not a question of him "understanding" the concept. Its more like him "agreeing" with it. Personally I dont agree with all of his views BUT I find them interesting. And some what possible. If you dont agree, then prove him wrong. And not by telling us your opinion. Or copying your text book explanations. Since we may not be as smart as you, this should be easy for you to do. You can even use small words if you want.

[MandoZink]

Sorry. I usually hang out at more academic physics and astronomy sites where people already understand most of the science involved. The posting I commented on would be normally considered lacking (or often crackpot. I forget this is a more of a science news outlet for the general public. My apologies. I should have taken that into consideration.

I don't have time to explain what is not understood by Ivar, but no insult is intended. My recommendation to do more research is still a good idea, however. There are some competent lecture series on YouTube. Once again, sorry about the tone of the original post.

[MandoZink]

"Those people who think they know everything are a great annoyance to those of us who do." - Issac Asimov

You might be glad I didn't say something like that.

[James Bain]

Even if they are correct, and the galaxy we inhabit collides with Andromeda, think it'll matter whether dark matter played a part in it.....? Assuming any of us are even there, of course, to witness the event and find those who disagreed and were proven wrong, just so we could say, "told you so!!!"???
Relax. Enjoy the show. Grab a lawn chair and a beer. Find a friend or two.

[Aline]

One thing is sure for me: when no more light is left,only Music will remain in the Universe...

[Issac Asimov]

MandoZink
If it makes you feel any better, your post here was also considered lacking and crackpot.

[Heliopause]

I hate to disappoint any of you, but MandoZink is entirely correct in assessment of the non-validity of Natural Philosopher's conjectures. There is a distinct lack of understanding of astrophysics inherent in Natural Philosopher's denial of this galactic merger event. The most basic motions of galaxies, gravitational attraction included, have been exceptionally well understood for decades. There is no doubt here. Natural Philosopher obviously has little, or no understanding of the fundamentals of astronomy that he needs to assert what he has claimed. To believe that his speculations have merit exposes your own lack of science education. You misunderstand both the science and the people who devote their life to give us a better comprehension of the universe we live in. Natural Philosopher's presumptions are, to put it mildly, uneducated nonsense. You should be better prepared in this life not to be misled by careless storytelling such as this.

[pi-r-round]

Well said, Helio. I concur. Sad, but entirely true. Illiteracy abounds and there are those who will defend it to the end.

[Yordan]

Probably during the calctic core merging - due to the riples, alot of side arms solar systems will be trown far away, becaming rogue solar systems, floating into the space alone.

It is much possible that some of the dwarf galaxies, which we are seen today have been born this way. :)

It is pretty cool way for a galaxy to be born this way actually.
Plus - I very think that since the dwarf galaxies usually doesnt harbor a black hole to endanger the stars, and their stars is pretty close each other, they offering a very nice conditions to became inteligent life long term hosts.

I think the dwarf galaxies shall be very checked about "interesting" signals.

;) I think i gave you enought brain food for now ..

[David]

I read that in 800 thousand years all the Carbon Dioxide will be gone from the earth and life as we know it will not exist so it seems that the mash up wont matter to any human or animal on earth by that time in the future

[Gaugain]

lol David so why didn`t it flew of in the 70 million years dinosaur era ? Now it will all evaporate in under 1 percent the time or life on earth lol

[DimcheSRQ]

I agree that 'dark matter' and 'dark energy' basically means "We have not the slightest clue what it actually is."

[Tom Mazanec]

Sigh...
it's four HUNDRED billion stars in the Milky Way galaxy.
Who proofreads these articles, anyway? Editor's Note: Hey Tom, what are you referring to? You sure you have the right article?

[martyn thompson]

Editor

However, recent observations by the Spitzer Space Telescope revealed that Andromeda contains one trillion stars, greatly exceeding the four billion stars in our own galaxy.

[SuperCluster Filaments]

What about the Asteroid Belt and the centaurs, Kuiper belt and scattered disk objects, and Oort cloud comets. Will those objects smash into our planets and moons?

[Headman]

Seems like the "experts" cannot agree on anything about the size of M31! One thing is very clear to me; they know nothing of the reality of the function of the cosmos!
If they did they would not make uninformed remarks of a merging of M31 with MW 4 billion years hence. A logical student of physics and astronomy would ask why ANY galaxies collide/merge in an EXPANDING universe! The not so simple answer is that the cosmos IS NOT a universe. Most physicists do not even understand true redshift, OR blueshift! Everyone understands redshift. BUT, do they understand that redshift is CAUSED by blueshift? No! Any galaxy that merges with another is obviously blueshifting, but, all galaxies redshift! There is a darn good reason for the anomaly of merging galaxies; there are also reasons for COLLIDING galaxies. Quasars are colliding galaxies, merging galaxies ARE NOT! Best you all look to the Virgoan supercluster and its massive blueshifting, and ask yourself the question: why is this the ONLY area in massive
blueshift? If you want to understand the COSMOS, start by throwing Einstein's theory in the trash! Don't believe me? Then remain forever mired in incorrect dogma, your choice!

[MandoZink]

Headman,
I just rediscovered these comments and must say you are quite misinformed about several things here:
1. Red-shift is NOT caused by blue-shift.
2. Quasars are NOT colliding galaxies. Quasars are compact regions in the centers of galaxies surrounding a supermassive black hole. They tend to be found in massive active young distant galaxies.
3. The expansion of the universe causes galactic red-shift to be small, or great, depending on it's distance from us, but the nearby galaxies in our Local Group are close enough to have either galaxies that are only slightly red-shifted, or galaxies that are blue-shifted if their relative movement (velocity) is TOWARD us, such as Andromeda.
4. Astronomers and physicists DO understand red-shift very well.
5. All observations of the universe in the last many decades have continuously shown Special Relativity and General Relativity to be quite correct.

How can you seem to be so interested and yet be so solidly uninformed?