Dark galaxy crashing into the Milky Way

[nebula]

Me: I wonder if stuff like this can account for some of the "dark matter"? I wonder why that wasn't mentioned in the article?

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Dark galaxy crashing into the Milky Way

* 22 November 2009

THE Milky Way's neighbourhood may be teeming with invisible galaxies, one of which appears to be crashing into our own.

In 2008, a cloud of hydrogen with a mass then estimated at about 1 million suns was found to be colliding with our galaxy. Now it appears the object is massive enough to be a galaxy itself.

Called Smith's cloud, it has managed to avoid disintegrating during its smash-up with our own, much bigger galaxy. What's more, its trajectory suggests it punched through the disc of our galaxy once before, about 70 million years ago.

To have survived, it must contain much more matter than previously thought, in order to provide enough gravity to hold it together. Calculations by Matthew Nichols and Joss Bland-Hawthorn of the University of Sydney, Australia, indicate that it has about 100 times the previously estimated mass (arxiv.org/abs/0911.0684).

Many more such dark galaxies may be out thereMovie Camera, says Leo Blitz of the University of California, Berkeley. Simulations of galaxy formation suggest a galaxy the size of the Milky Way should feature about 1000 dwarf galaxiesMovie Camera, but only a few dozen have been found so far. Some of the missing dwarfs may be dark galaxies that are all but invisible, he says.

Source

More info, if you are interested

[wyguy]

I'm not worried about it. God is in control.

Interesting article though.

[Fez]

Dark matter is such interesting stuff, no one except God knows what it is yet, but it takes up most of the universe. How cool is that!

[JCMS]

Extremely interesting article! Thank goodness God is in control!

[georgedrw81]

I'm not worried about it. God is in control.

Right

[ellarose]

Nebula, do you think you could possibly explain the vibe of the article and implications? I'm probably just too tired but I didn't understand it, lol.

For instance, when are we meant to be colliding?

[nebula]

What I am understanding is that this is simply a gas cloud of hydrogen. It's not really a galaxy, they're just saying that because it is large enough to be a galaxy. (Well, they're also calling it that based on how they believe galaxies form...the hydrogen just never coalesced to form anything.)

It sounds like the cloud is already "crashing into" our galaxy. But keep in mind that this isn't like a car crash. There is a whole lot of space between stars (the nearest star to us is about 4.2 light years away . . . that's a lot of room for hydrogen ions to pass through!).

Collectively, yes there is a lot of gravity involved, but in a local area (i.e. a solar system), I'm not sure how much a gravity pull or shifting of things we'd have to worry about.

Does that clarify things?