Slashdot Mirror
Huge Hydrogen Cloud Will Hit Milky Way
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."
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.
I live in constant fear of the Coming of the Red Spiders.
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?
Chelloveck
I give up on debugging. From now on, SIGSEGV is a feature.
Well, the milky way does have intelligent life. Their intelligence can be seen by the fact that they didn't get in contact with us.
The Tao of math: The numbers you can count are not the real numbers.
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!
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?The Tao of math: The numbers you can count are not the real numbers.
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...
The creatures outside looked from Alt-Right to Antifa; but already it was impossible to say which was which.
You know what these high-fiber diets do to you.
Anybody want my mod points?
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.
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.
don't cut it off www.mgmbill.org
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.
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.
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?
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
First God gives us the finger, and then he farts our way. He must be trying to tell us something about our conduct.
Table-ized A.I.