Impact with Andromeda

[vintersorg]

Would the impact with Andromeda galaxy be fatal for humankind? Assuming it still exists, which it most likely won't.<br />When two galaxies impact, it's unlikely its stars will actually colide due to the huge gaps between them, is it not? Then, what would happen to a star like the Sun or a planet like Earth and the things that inhabit it? Thanks.

 

[3488]

You are spot on.<br /><br />It is a merger rather than an impact. The space between individual stars<br />is great & the chance, though it cannot be ruled out of collisions is very, very small.<br /><br />In fact, this poses only a small risk to our own solar system. At this point the Sun will be<br />reaching towards the end of its Main Sequence stage & will be a little hotter & brighter than now.<br /><br />The biggest threat is the ageing Sun rather than M31.<br /><br /><img src="/images/icons/laugh.gif" /> <img src="/images/icons/laugh.gif" /> <img src="/images/icons/laugh.gif" /> Happy Boxing Day everyone. <img src="/images/icons/laugh.gif" /> <img src="/images/icons/laugh.gif" /> <img src="/images/icons/laugh.gif" /><br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[MeteorWayne]

It's 99.999% we will pass through without an effect.<br /><br />Of course, there's that other 0.0001% <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[brellis]

It might cause an Andromeda Strain on life as we know it <img src="/images/icons/tongue.gif" /><br /><br />More seriously, I wonder if there will be any black hole fireworks like the jet Chandra spotted the other day. <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[billslugg]

Is the merger scheduled for weekend? Hopefully I'll be off. Sounds like quite a show. If the Earth actually hits another star, will it be visible from NW Albany, GA? <div class="Discussion_UserSignature"> <p> </p><p> </p> </div>

 

[weeman]

3488 is correct. Considering that the diameters of stars ranges from tens of thousands to tens of millions of miles, gives a good chance that the majority of the stars in the galaxies would not collide since all stars are seperated by at least a few lightyears. <br /><br />The closest star to us (other than the Sun) is Alpha Centauri, which sits about 4 lightyears away. At 1.4 million kilometers wide, just think how many of our suns you could fit in that distance. <br /><br />And I don't think you have to worry about the two galaxies merging. Mankind, along with all life on Earth, should be long gone by then, due to the changes in the Sun's size and temperature (just as 3488 said <img src="/images/icons/smile.gif" /> ). <br /><br />That is unless we become so advanced that we become an intergalactic species who lives on multiple planets in other solar systems at the time of the collision. <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">Techies: We do it in the dark. </font></strong></p><p><font color="#0000ff"><strong>"Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity.</strong><strong>" -Albert Einstein </strong></font></p> </div>

 

[qso1]

Colliding galaxies are a popular topic with writers reporting on astronomy. They tend to make it sound as though these collisions, or mora accurately mergers, would be like two cars slamming into each other.<br /><br />If we could speed up time, then galaxies would appear to be merging rapidly which if humanity lived on that kind of time scale, it would possibly be fatal.<br /><br />The only way I can see a galactic merger being fatal to humans or any life forms is if planets and/or stars slam into other planets or stars from either galaxy or some stars with immense radiation feilds pass nearby. As you mentioned, it is highly unlikely that most stars would collide because of the immense space between them.<br /><br />The time scale would also be so slow that it would be next to impossible to know when the galaxies actually start merging to when the full merger is underway. A process not nearly as exiting as the galaxy collision writers would like. Towards the center of each galaxy involved in the merger, collisions of individual stars planets etc. would be occuring more assuming the galactic centers come close to merging. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[alkalin]

There is the fictional belief that galaxies just merge somehow.<br /><br />It is known Andromeda is generally heading in our direction but not yet known how close the MW and Andromeda get. If someday they do pass through, it could be a very disruptive process for these two galaxies indicated by a few times we have seen other galaxies pass through each other. Fortunately it is not a very common occurrence. <br /><br />If it did happen, contact between Milkywayans and Andromedians might then be possible as we glide by each other. The bad news is we are located far from the center so the entire arm of the MW where we live might be pulled apart if our area coincided most directly with Andromeda. I think chances of actual collisions between stars at that time increases just a little. If this were to happen our sun would very likely still be there with all the planets but thrown out of the gravitational influence of the MW<br /><br />

 

[bearack]

But isn't Adrameda a larger galaxy than our own and wouldn't or couldn't their gravitational drag impact our own is some manner? <br /><br />EDIT: If I would had read through all of the thread, I might have answered my own question <img src="/images/icons/wink.gif" /><br /> <div class="Discussion_UserSignature"> <p><br /><img id="06322a8d-f18d-4ab1-8ea7-150275a4cb53" src="http://sitelife.space.com/ver1.0/Content/images/store/6/14/06322a8d-f18d-4ab1-8ea7-150275a4cb53.Large.jpg" alt="blog post photo" /></p> </div>

 

[dragon04]

The biggest potential problem will be the radiation generated due to accelerated star formation as the two galaxies merge.<br /><br />The interaction between M31 and the MW might lead to a Starburst Galaxxy <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[garfieldthecat]

Actually, from the studies I’ve read, we know MW and Andromeda are getting closer from each other, at a speed of about 75 miles per second, but there is still high uncertainty on the precise course of the two galaxies. We may actually get closer, but not collide, like two cars rolling at each other but on two different lanes.<br /><br />If it happens, the gravitational effects may be strong enough to modify the course of the Sun around the galactic centre, but not to tear the planets apart of the solar system, or influence greatly their trajectory.<br /><br />Also, M31 contains more stars than our MW but appears lighter, according to the last studies. This could be due to the fact that MW got more dark matter, but also because M31 just passed through a high rate star formation period. So MW seems to be the bigger and heavier of the two<br />N. W. Evans & M. I. Wilkinson (2000). "The mass of the Andromeda galaxy". Monthly Notices of the Royal Astronomical Society 316 (4): 929–942.<br /><br />As far as I get it, this question of M31 and MW collision is still highly debated amongst the scientific community.<br />

 

[MeteorWayne]

Good points.<br /><br />And another is that none of us will be alive, and to be honest, the solar system will no longer exist in it's current form due to the Red Giant phase of our star disrupting (and in some cases frying) the planets well before any pre-merger interaction.<br /><br />So while it's fun to speculate, it really makes not a whit of difference to our (or even our progeny's) lives.<br /><br />Perhaps in a few billion years, if our species has spread throughout the galaxy, it might be significant. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[bearack]

Isn't it true that our sun is in it's reduction stage and will soon (I mean millions if not billions of years) start its expansion onces it starts to turn into a red dwarf or am I incorrect? <div class="Discussion_UserSignature"> <p><br /><img id="06322a8d-f18d-4ab1-8ea7-150275a4cb53" src="http://sitelife.space.com/ver1.0/Content/images/store/6/14/06322a8d-f18d-4ab1-8ea7-150275a4cb53.Large.jpg" alt="blog post photo" /></p> </div>

 

[MeteorWayne]

Yes, in 4 or 5 billion years the sun will deplete it's Hydrogen and will begin to expand as other fusion reactions occur. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[bearack]

Not to get of subject here and I won't pose any further questions regarding this after this last question.<br /><br />If our sun expands, could potentially Mars re-enter into a habital zone with the the surface warming. Granted, I know (or at least speculate) that the core is cooled, but the scenerio interest me.<br /><br />Thanks in advance for all the information! <div class="Discussion_UserSignature"> <p><br /><img id="06322a8d-f18d-4ab1-8ea7-150275a4cb53" src="http://sitelife.space.com/ver1.0/Content/images/store/6/14/06322a8d-f18d-4ab1-8ea7-150275a4cb53.Large.jpg" alt="blog post photo" /></p> </div>

 

[brellis]

<font color="yellow">M31 contains more stars than our MW but appears lighter, according to the last studies. </font>- M31 is much bigger, but less dense, than the MW.<br /><br />From a physorg article:<br /><font color="yellow">"The physical size of this galaxy is really striking," said coauthor R. Michael Rich of UCLA. "The suburbs of M31 and the Milky Way are so extended that they nearly overlap in space, despite the great distance between these two galaxies. If the whole of M31 were bright enough to be visible to the naked eye, it would appear to be huge, larger in apparent size than the Big Dipper." </font>/safety_wrapper> <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[brellis]

hi Bearack<br /><font color="yellow">If our sun expands, could potentially Mars re-enter into a habital zone with the the surface warming.</font>- The folks at NASA think so! <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[3488]

But only for avery brief period before Mars too becomes too hot. <br /><br />Remember, although Mars may well be in the Goldilocks Zone of the ageing Sun, lack of<br />global magnetosphere, small mass & lesser gravity means that any thickening <br />of the Martian atmosphere due to volatiles being evaporated, will be largely offset<br />by the Sun's then ferocious Solar Wind, which will be stripping it away just as quickly. <br />So really, this is a moot point.<br /><br />So yes, it is true that Mars will be in the Goldilocks Zone, before that moves <br />outwards into the Asteroid Belt.<br /><br />No, Mars will never be a second Earth. It is just too different.<br /><br />Mars will be next to useless in reality. A temporary stop gap, before us leaving the solar system, <br />but Mars in a relatively short period will become like our Moon or Mercury, under such a <br />powerful Sun.<br /><br />People should not really think of Mars, being a substitute for Earth. It has barely <br />11% of the mass of Earth, with a surface gravity of 37%.<br /><br />Mars is not like Earth.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[brellis]

<font color="yellow">But only for avery brief period before Mars too becomes too hot. </font><br /><br />offhand, i'll disagree, Andrew. I won't try to find all the ref's to back it up, but if there is some kind of microbial life (or potential life, seeds of life, etc.) on Mars, wouldn't there be a billion years of Miami-like weather under a Red Giant Sun during which it might advance?<br /><br />It only took 600 million years for life to advance as far as we have...<br /><br />methinks <img src="/images/icons/crazy.gif" /> <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[pyoko]

I was wondering if with the number of stars and the distances between them, what is the probability that ONE collision will occur? <div class="Discussion_UserSignature"> <p> </p><p> </p><p><span style="color:#ff9900" class="Apple-style-span">-pyoko</span> <span style="color:#333333" class="Apple-style-span">the</span> <span style="color:#339966" class="Apple-style-span">duck </span></p><p><span style="color:#339966" class="Apple-style-span"><span style="color:#808080;font-style:italic" class="Apple-style-span">It is by will alone I set my mind in motion.</span></span></p> </div>

 

[qso1]

With an estimated 400 billion stars in our galaxy alone...I'd say the chance of a star collision is remote, but high enough for at least one collision to occur and more than likely...several collisions. And it may also be possible for galaxies to merge so to speak, without any stars colliding. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[thalion]

Several things:<br /><br />1.) As others have mentioned, it would take millions of years, so there would be no sudden and dramatic "switch" to collision conditions.<br /><br />2.) By far the biggest effect of the collision would be the creation of a "starburst" galaxy, as M 31's and the Milky Way's gas clouds collide and trigger a furious round of star formation. This would be truly spectacular: lots of interstellar dust clouds and emission nebulae, hordes of bright, massive stars, a supernova rate tens or hundreds of times higher than it is in either galaxy today.<br /><br />3.) In the end, the Sun's orbit would be several disrupted as the starburst died down and the two galaxies merged into a relatively bland giant elliptical galaxy. It's possible we'd be flung into intergalactic space--albeit so gently that there would be no disruption to the Solar System--or we could be flung out into a eccentric orbit taking us from the galaxy's outskirts to the dense inner regions. In any event, there's no way to predict the exact outcome at this time.

 

[pyoko]

OK. So it's remote but will almost definitely happen lol.<br />Someone want to do the maths? M31 contains one trillion (10^12) stars and the Milky Way has 400 billion stars. If we assume the average distance between stars is 10 light years, how many stars, on average, would collide?<br /><br />Or do you need a supercomputer for this kind of thing? <div class="Discussion_UserSignature"> <p> </p><p> </p><p><span style="color:#ff9900" class="Apple-style-span">-pyoko</span> <span style="color:#333333" class="Apple-style-span">the</span> <span style="color:#339966" class="Apple-style-span">duck </span></p><p><span style="color:#339966" class="Apple-style-span"><span style="color:#808080;font-style:italic" class="Apple-style-span">It is by will alone I set my mind in motion.</span></span></p> </div>

 

[adrenalynn]

Modeling that would require more than one of those... Computing the angle of attack and the probable gravitational interaction of 10.4 trillion massive bodies? Ouch. <div class="Discussion_UserSignature"> <p>.</p><p><font size="3">bipartisan</font>  (<span style="color:blue" class="pointer"><span class="pron"><font face="Lucida Sans Unicode" size="2">bī-pär'tĭ-zən, -sən</font></span></span>) [Adj.]  Maintaining the ability to blame republications when your stimulus plan proves to be a devastating failure.</p><p><strong><font color="#ff0000"><font color="#ff0000">IMPE</font><font color="#c0c0c0">ACH</font> <font color="#0000ff"><font color="#c0c0c0">O</font>BAMA</font>!</font></strong></p> </div>

 

[pyoko]

Simplify it. Forget the true angle. Assume the two galaxies are cubes. <div class="Discussion_UserSignature"> <p> </p><p> </p><p><span style="color:#ff9900" class="Apple-style-span">-pyoko</span> <span style="color:#333333" class="Apple-style-span">the</span> <span style="color:#339966" class="Apple-style-span">duck </span></p><p><span style="color:#339966" class="Apple-style-span"><span style="color:#808080;font-style:italic" class="Apple-style-span">It is by will alone I set my mind in motion.</span></span></p> </div>