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Huge Hydrogen Cloud Will Hit Milky Way
Posted by
Soulskill
on Sun Jan 13, 2008 12:12 PM
from the doomsday-asteroids-werent-enough dept.
from the doomsday-asteroids-werent-enough dept.
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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Hindenstromics (Score:3, Funny)
Shot in the Dark (Score:5, Interesting)
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Re:Shot in the Dark (Score:5, Funny)
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Re:Shot in the Dark (Score:5, Funny)
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Re:Shot in the Dark (Score:5, Funny)
Interesting example. I would have used the puppy vs large wood chipper example.
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I don't think it means what you think it means... (Score:5, Insightful)
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?
Re:I don't think it means what you think it means. (Score:5, Informative)
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?
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Re: (Score:3, Informative)
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Gravitation is an interaction force (Score:5, Insightful)
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.
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Re:Gravitation is an interaction force (Score:4, Informative)
The four forces are an entirely different matter. Electromagnetism, the strong and weak forces are summed up in the Standard Model of Particle Physics (in the form of the Electroweak Theory + Quantum Chromodynamics), which is very well tested and in fantastic agreement with experiments. Gravity doesn't fit into the mathematical framework of quantum mechanics, but the theory of General Relativity has been tested experimentally and is almost universally accepted.
So that's basically the reason... You have four interactions for which we have very well tested theories and mathematical tools, while we know almost knothing about Dark Energy except for the fact that we need it to make our cosmological models work
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Re:I don't think it means what you think it means. (Score:5, Funny)
I bet quite a number of folks will stock up on gas masks when they'll hear these news...
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Oh come on. By now you should know the only deadly gas is CO2.
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Re:I don't think it means what you think it means. (Score:3, Interesting)
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Has this happened before - in "recent" times? (Score:5, Interesting)
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?
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Hydrogen economy (Score:5, Funny)
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A warming thought (Score:2)
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
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fuel for the fire (Score:2, Interesting)
Awesome! (Score:2, Funny)
Sorry about the cloud, guys (Score:4, Funny)
Huge Gas Cloud Will Hit Milky Way (Score:2, Funny)
This is extremely important (Score:5, Funny)
Re:This is extremely important (Score:4, Funny)
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furlongs and donkey forthnights (Score:5, Informative)
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.
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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.
MegaMaid (Score:2, Funny)
Life that one down, Milky Way. (Score:5, Funny)
Don't expect to be invited to too many parties in the 20,002,007AD-40,002,007AD season.
Everyone ... (Score:2)
Just in time (Score:2)
hudrogen rush (Score:4, Funny)
God's Fart (Score:5, Funny)
You wanted hydrogen fuel? Here you go. (Score:3, Funny)
What next? A Cloud of Oxygen. (Score:3, Interesting)
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?
Re:Shame (Score:5, Funny)
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You sure it's intelligence? (Score:3, Funny)
"Oh, like, those Sol guys are, like, soo nerdy, always with their, like, radio-teles-wossnames and their gizmos. And, like, God, they just can't take a hint when they're, like, not wanted. You'd think, like, after they got ignored a dozen times, they'd, like, quit trying to get our attention already. I mean, gah, gag me with a spoon, like I'd ever w
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Who is doing the rectal probing?
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Re:Stock Market and Banks (Score:4, Funny)
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When they are confronted with it somehow, they either ignore it or pull out some variety of Last Thursdayism: the universe was created with all of the bits already in motion, and the light from distant stars already underway, and the fossils neatly buried. Rationalisations as to the reasons for this range from "test of faith" to "giving us something to look at in the night sky".
Remember: evidence against s