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Space Science

Huge Hydrogen Cloud Will Hit Milky Way 220

diewlasing points us to a story about a hydrogen cloud, eleven thousand light-years long, which will collide with the Milky Way in a devastating crossfire of shock waves and star formation...in 20-40 million years. Mark your calendars. At least it will give us something to watch while we're waiting for Andromeda to hit us in a few billion years. Hopefully, it will look at least this cool. "The detailed GBT study dramatically changed the astronomers' understanding of the cloud. Its velocity shows that it is falling into the Milky Way, not leaving it, and the new data show that it is plowing up Milky Way gas before it as it falls. 'Its shape, somewhat similar to that of a comet, indicates that it's already hitting gas in our Galaxy's outskirts,' Lockman said. 'It is also feeling a tidal force from the gravity of the Milky Way and may be in the process of being torn apart. Our Galaxy will get a rain of gas from this cloud, then in about 20 to 40 million years, the cloud's core will smash into the Milky Way's plane,' Lockman explained."
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Huge Hydrogen Cloud Will Hit Milky Way

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  • by Chairboy ( 88841 ) on Sunday January 13, 2008 @12:16PM (#22026004) Homepage
    Oh the hugegalaxy!
  • Shot in the Dark (Score:5, Interesting)

    by Amorymeltzer ( 1213818 ) on Sunday January 13, 2008 @12:19PM (#22026044)
    It seems to me that something with enough gas to create 1M stars akin to the Sun might have a noticeable impact on the revolutionary nature of the galaxy. Nothing astounding, probably akin to the added wobble of the Earth after the giant 2004 earthquake (the one that caused the tsunami) but it's probably something that, on the off chance we or some other life form is around, would be really awesome to observe. Also, assuming we don't have all the answers yet, seeing how the galaxy responds to such a sudden, massive change compared to our models could really tell us exactly how much mass there is, how it's distributed, etc.
    • Re: (Score:3, Interesting)

      by kestasjk ( 933987 )
      What's interesting is that apparently they don't know where it came from, and it's supposedly strange to just have a relatively small cloud of hydrogen coming towards us from a totally empty area of space.
      • Re: (Score:3, Funny)

        by king-manic ( 409855 )

        What's interesting is that apparently they don't know where it came from, and it's supposedly strange to just have a relatively small cloud of hydrogen coming towards us from a totally empty area of space.
        God, Cthulu, and the FSM went to a Mexican place for lunch.
    • Re: (Score:2, Insightful)

      by Anonymous Coward

      It seems to me that something with enough gas to create 1M stars akin to the Sun might have a noticeable impact on the revolutionary nature of the galaxy. Nothing astounding, probably akin to the added wobble of the Earth after the giant 2004 earthquake

      Probably not so much. The difference is that the Earth is a rigid object, while the galaxy is a swirling pile of unconnected particles. It would take a very long time for tidal locking to redistribute the energy.

    • I've often wondered if doing stuff like harvesting tidal energy would mess up the tides enough to disrupt the orbit of the moon or somesuch. There's no such thing as a free lunch!
  • by Chelloveck ( 14643 ) on Sunday January 13, 2008 @12:30PM (#22026118)

    Does anyone else have a problem with the word "smashing" to describe the contact of two bits of not-quite-vacuum passing through each other?

    • by maxwell demon ( 590494 ) on Sunday January 13, 2008 @12:34PM (#22026180) Journal

      Does anyone else have a problem with the word "smashing" to describe the contact of two bits of not-quite-vacuum passing through each other?

      You mean, like a stone smashing into a window? You don't actually think the electrons or atomic nuclei of the stone actually come into contact with the electrons or atomic nuclei of the window, do you?
      • Re: (Score:3, Informative)

        by Anonymous Coward
        It's not a matter of coming into contact (at the smallest level, every elementary particle may well be mathematical points), but of getting close enough for an interaction force to be produced.
        • Re: (Score:3, Insightful)

          by donaggie03 ( 769758 )
          I'm pretty sure that was exactly his point. He's saying that an interaction force would be produced when this astronomical event occurs, therefore the word "smashing" would apply just as much as it applies when dealing with rocks and windows.
        • by mangu ( 126918 ) on Sunday January 13, 2008 @02:19PM (#22027128)

          close enough for an interaction force to be produced

          There are four known forces in the universe, the weak and strong nuclear forces are short-range, while the electrical and gravitational forces are long-range, which means they will produce interactions everywhere in the universe.


          Electrical forces come in two polarities, positive charges balance out negative charges, but gravitational forces always add up. There's no known way to block gravitation, therefore one can say that any two galaxies in the universe are "close enough for an interaction force to be produced", given enough time.


          In the context of the article, I suppose "smashing" means close enough to produce significant distortion in the overall shape of the hydrogen gas cloud.

          • by LWATCDR ( 28044 )
            "There are four known forces in the universe, "
            I thought that they unified the electromagnetic and the weak force into the electro-weak force.
      • I'm pretty sure we're talking about a description of what it looks like, not the technical details of the actual physics involved -- no need to show off your knowledge of sub-atomic theory.
      • by mqduck ( 232646 )

        You mean, like a stone smashing into a window? You don't actually think the electrons or atomic nuclei of the stone actually come into contact with the electrons or atomic nuclei of the window, do you?
        Me? Yes, but I get the feeling I'll look stupid if I say so. ....Oops.
      • Since it's the Pauli exclusion principle (rather than electrostatic interactions) that makes solid matter solid, in a sense, the electrons and atomic nuclei do actually "come into contact". The notion of the atom as being a tiny electron buzzing around a tiny nucleus is as much as a myth as the "we only use 10% of our brain" notion.
    • by KiloByte ( 825081 ) on Sunday January 13, 2008 @12:37PM (#22026206)
      It's gas! It's deadly! Protect yourself! Protect your kids!

      I bet quite a number of folks will stock up on gas masks when they'll hear these news...
      • Re: (Score:3, Funny)

        by letxa2000 ( 215841 )

        It's gas! It's deadly! Protect yourself! Protect your kids!

        Oh come on. By now you should know the only deadly gas is CO2.

        • Meh, If someone were to actually say that one would just remind them of beans =)
        • What!?!? The content of this stuff in fresh air already varies between 0.03% (300 ppm) and 0.06% (600 ppm), and I'm running out of duct tape! :O
          • Re: (Score:3, Funny)

            It's easy. Just use the last several inches to cover your mouth and nose. That'll be sure to keep all those nasty gases out! Problem solved!
    • Maybe people who don't understand what will happen will have a problem. Like the kind of people that think they will simply pass through each other. What really happens is that colliding clouds form a shock front and can heat up to millions of degrees C.
      • Re: (Score:3, Interesting)

        by greginnj ( 891863 )
        I think the question that the original poster raised is best expressed as, "can someone give a description of this 'gas cloud' in terms of average units of mass per units of volume?" And perhaps adding in "what is the total volume of this cloud, if we consider the boundary of the cloud as the zone where local mass-per-unit-volume descends to 10% of average mass-per-unit-volume?" While your point may be technically correct, talking about a temperature of millions of degrees C for such a sparse cloud would m
      • Re: (Score:2, Insightful)

        by osu-neko ( 2604 )

        Two points:
        (1) The sun's outer atmosphere is already in the millions of degrees.
        (2) Our planet orbits within the sun's outer atmosphere.

    • by Ungrounded Lightning ( 62228 ) on Sunday January 13, 2008 @04:22PM (#22028060) Journal
      Does anyone else have a problem with the word "smashing" to describe the contact of two bits of not-quite-vacuum passing through each other?

      I don't. (At least not until I find out the relative masses and densities of the gas cloud vs. both the sections of the Milky Way it's about to encounter and the interstellar-gas components of them.)

      The cloud may be a very hard vacuum - only slightly softer than the intergalactic space around it. But at galactic scales it still amounts to something quite dense and massive, which will not pass through the interstellar gas and solar winds of our galaxy without interacting repeatedly - let alone through the magnetic fields of the galaxy and the stars and planets that compose it.

      I'd expect it to coalesce with the galaxy. That much mass at that much relative velocity will dump enormous amounts of energy into compression and heat at the shock front (similar to the graduation of "falling pebble" to something akin to a bomb when the pebble is falling at cometary speed, or a nuclear bomb when the "pebble" is also a couple miles in diameter). The energy density might be small, but over half the sky the radiant temperature can add up. Over that much matter, even at near-vacuum densities, even fusion events could be non-trivial - especially since magnetic effects could produce concentrations.

      In gas clouds I'd expect it, at a minimum, to kick off a round of star formation. Also to sweep the gas and dust out from between existing stars and their planetary systems (and fractionate it), as dense accumulations are accellerated little while gas and dust encounter something of comparable density.

      Even if the density is so low that the above effects aren't significant for planetary systems like ours, the passage of the cloud (especially the shock front) would wreak non-trivial havoc on the solar wind and magnetosphere - and thus planetary radiation shielding. Because the solar wind -> radiation shielding -> water condensation nucleation -> cloud cover -> solar heat reflection connection seems to be a major contributor to (geologically) short-term planetary temperature changes, the arrival and passage of the gas cloud could have a major effect on climate. (Even if its impact on the magnetosphere doesn't "stir up" some change in activity on the solar surface or modify the sunspot cycle.)

      Which brings up the questions:
        - Have similar events occurred in the geologically "recent" past?
        - If so, do they have any relation to ice ages and interglacial periods or to mass extinction events?
      • There are lots of papers about "fossil galaxies" lurking in the Milky Way. Often its a a cluster or cloud with an unusual internal orbital trajectory/velocity. This means it hasnt reach an equilibrium state since merger and converted to a normal orbit.
    • Well, when it his (comes into contact, if you prefer) it's expected to cause shock waves that will trigger a burst of star formation. Many of those stars will be large, which will then supernova in short order.

      Sounds like a smashing good time to me.
  • by ShadeOfBlue ( 851882 ) on Sunday January 13, 2008 @12:33PM (#22026162)
    This is god's answer for all those people who said hydrogen was just an energy storage mechanism, not a solution to the energy crisis. Look, there's untold millions of barrels of the stuff headed our way!
    • Re: (Score:3, Funny)

      by KiloByte ( 825081 )
      Why would we wait that long? Hey, there's a decent ball of the stuff just mere 8 light minutes away...
  • that the hydrogen gas cloud exists - it means that there is material for a lot of new stars to form yet.

    Time to bring out the spaceship and start spreading humanity into the galaxy. :-)

    But when the cloud hits humanity will have disappeared and diverted in so many different forms that it's probably not interesting anymore. But is humanity at it's height right now? Inhumanity sure is!

    On a geological timeframe humanity is insignificant, and on a universal scale we are merely a static crack. That we still

    • If our descendants are still around in 40 million years, and especially if they have diversified into many different forms, I'm pretty confident things overall will be "interesting". If even one of those forms preserves and extends technological civilization, minor things such as gas clouds will also be completely safe for transhumanity.
    • by nguy ( 1207026 )
      On a geological timeframe humanity is insignificant, and on a universal scale we are merely a static crack

      That remains to be seen; humanity is very young, but it has the potential of lasting billions of years and spreading across the galaxy.
      • Billions of years? Please. If humanity survives the next 10,000 years I expect it to come up with a way of destroying the universe as a whole. Mere centuries left after that.
  • fuel for the fire (Score:2, Interesting)

    Hey, that's just the fuel we'll need for a Bussard ramjet [wikipedia.org]
  • Awesome! (Score:2, Funny)

    by Anonymous Coward
    Something to watch while were waiting Duke Nukem Forever
  • by russlar ( 1122455 ) on Sunday January 13, 2008 @01:03PM (#22026440)
    You know what these high-fiber diets do to you.
  • God wishes to extend an apology to all inhabitants of the Milky Way for the after effects of the Chilli and Beans he consumed a while ago....
  • by edwardpickman ( 965122 ) on Sunday January 13, 2008 @01:25PM (#22026678)
    We need to start building ships and load them full of our most important people. Politicians, Lawyers and phone sanitizers. It would best not to wait until the hydrogen hits these people are far too important and should be saved now! The future of our civilization depends on it!..... We'll start building ships for the rest of us when they are safely on their way.
  • by viking80 ( 697716 ) on Sunday January 13, 2008 @01:59PM (#22026966) Journal
    Here is just some useful unit conversations:
    suns = 2E30 kg
    light year = 1E16 meters
    So this cloud has a density of 28 H2 molecules per liter.
    That is pretty good vacuum. Actually about a million times better vacuum than "deep vacuum" in outer space here in our solar system, which again is much better vacuum than what is achievable here on earth.

    So this "collision" will be quite soft in terms of energy density: One feather landing on an area the size of the earth.
    • Re: (Score:3, Interesting)

      by RealUlli ( 1365 )
      Disclaimer: I didn't read the article.

      So this "collision" will be quite soft in terms of energy density: One feather landing on an area the size of the earth.

      Right at first, yes. But there will be collisions, there will be gravity interaction.

      There also is the fact that (1000000 suns x 2e30 kg = 2e37 kg) of mass coming in at 150 miles/second contain a *lot* of energy...

      Some of that mass will combine with the gas in milkyway and push some areas over the threshold into collapsing and forming stars.

    • Using Kilograms and meters to describe astronomical masses and distances is like using nanometers to describe the distance between London and New York. It's pretty silly, isn't it?

      This is why a few new conventions were adopted. A "Solar mass" is indeed a valid measurement of stars, nebulae, galaxies, and black holes. The only difference is the language used to describe such things in press releases, since the public doesn't actually know what a solar mass *is*.

      There are also astronomical units, which is the
      • by proxima ( 165692 )

        Using Kilograms and meters to describe astronomical masses and distances is like using nanometers to describe the distance between London and New York. It's pretty silly, isn't it?

        You'd think that, but professional astronomers use some seemingly-bizarre units sometimes (though IANAPA). For example, they sometimes use centimeters (obviously with scientific notation). What I don't get is why they don't use the "base" unit of meters, but there you go; it's probably some historical oddity, or who knows, they

        • Astronomers often use CGS (Centimeters, grams, seconds) instead of MKS (meters, kilograms, seconds) because it makes the calculations easy. "CGS units are still occasionally encountered in technical literature, especially in the United States in the fields of electrodynamics and astronomy. SI units were chosen such that electromagnetic equations concerning spheres contain 4, those concerning coils contain 2 and those dealing with straight wires lack entirely, which was the most convenient choice for electr
  • MegaMaid (Score:2, Funny)

    by __aaqvdr516 ( 975138 )
    If in 20-40 million years we're still having an energy problem I'll recommend breaking out MegaMaid. Let's make sure she's set to suck (not blow) so we can collect all of this hydrogen to use in our H2 powered vehicles :) I better get cracking on canning air to sell to the Spaceballs in payment for MegaMaids services.
  • by nick_davison ( 217681 ) on Sunday January 13, 2008 @02:01PM (#22026988)
    If there's one thing I find more embarrassing than gas trapped in my outskirts, it's when it causes a "devastating crossfire of shock waves and star formation." It's almost impossible to blame on the dog.

    Don't expect to be invited to too many parties in the 20,002,007AD-40,002,007AD season.
  • ... light a match as the cloud goes by.
    • by Boronx ( 228853 )
      Great idea, then we can collect precious Phlogiston as it is burned out of the cloud.
  • Just in time to fuel the "hydrogen economy"!
  • by wikinerd ( 809585 ) on Sunday January 13, 2008 @03:31PM (#22027704) Journal
    now it's time for the hydrogen economy!
  • 20 million years? (Score:2, Insightful)

    by philspear ( 1142299 )
    Do you think by then we'll be able to make a black hole and shoot it in the direction of the cloud to suck it up before it hits us?

    I realize there are probably other ways to keep it from hitting our solar system, but I'd like us all to agree right here and now that a black hole cannon is how we are going to deal with this, just so we're all on the same page and can get our act together in time.
  • Don't anybody light a match!
  • God's Fart (Score:5, Funny)

    by Tablizer ( 95088 ) on Sunday January 13, 2008 @05:07PM (#22028414) Journal
    First God gives us the finger [nasa.gov], and then he farts our way. He must be trying to tell us something about our conduct.
       
    • Comments from NASA: "This Carina sub-cloud is particularly striking partly because its clear definition stimulates the human imagination (e.g. it could be perceived as a superhero flying through a cloud, arm up, with a saved person in tow below)."

      Oh, bugger, that made my day :)
  • by Venik ( 915777 ) on Sunday January 13, 2008 @05:59PM (#22028912)

    Our Galaxy will get a rain of gas from this cloud...
    Not if Gazprom gets to it first.
  • Don't Panic
  • a hydrogen cloud, eleven thousand light-years long, which will collide with the Milky Way
    It's coming right for us.
  • by o0OSABO0o ( 937312 ) on Sunday January 13, 2008 @07:05PM (#22029464)

    If a cloud of oxygen of the same size were to come at the Milky Way from the opposite size, would the resulting cloud of water be enough to put out all of the stars?

  • The detailed GBT study dramatically changed the astronomers' understanding of the cloud

    Can someone tell me what the Gay, Bisexual and Transgender study has to do with astrophysics? Or were the astronomers just assuming the cloud was "hetro", and now they understand it better?

  • A devastating crossfire of shock waves and star formation

    ...

    smash into the Milky Way's plane

    These are rather heavy words for the fact that a rather rarified cloud of gas is going to seep in between the stars in our galaxy. Even in the highly unlikely event that there are humans around when this begins to happen, we wouldn't notice on a day to day basis. A star system takes long to form, in human terms, in the order of 100,000 to millions of years. Even the collision between two galaxies is not something that anybody would notice in their daily lives.

  • Hopefully, it will look at least this cool [hubblesite.org].
    Entirely depends on your point of view. Literally.
  • Although this is quite a ways off, I am still curious whether this or some other event is going to make the earth uninhabitable. My understanding was that our planet had at least a couple of billion years left in it. Reducing that to 40 million is significant, even if it doesn't effect this years elections.
  • Over my cold dead decomposited reincarnated (multiple times) body, it will!!

"I'm a mean green mother from outer space" -- Audrey II, The Little Shop of Horrors

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