Dark galaxy crashing into the Milky Way

Dark galaxy crashing into the Milky Way

www.newscientist.c om

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

(visit the link for the full news article)

Sorry if I am posting this on the wrong board.


Should we be worried about this. I don't know much about dark Galaxies and if they have any gravity pulls or whatever but this is certainly bigger than Planet X.

And also the article says:

"What's more, its trajectory suggests it punched through the disc of our galaxy once before, about 70 million years ago."

did we have any mass extinction 70M years ago??????


I wonder what other things are invisible lurking close to us we don't know about......

www.newscientist.c om
(visit the link for the full news article)

Originally posted by rattan1
did we have any mass extinction 70M years ago??????

Close... give or take a few million.

Cretaceous–Tertiary extinction event (K-T extinction) - 65 Ma at the Cretaceous-Paleogene transition about 17% of all families and 50% of all genera went extinct.[4] (75% species). It ended the reign of dinosaurs and opened the way for mammals and birds to become the dominant land vertebrates. In the seas it reduced the percentage of sessile animals to about 33%. The K-T extinction was rather uneven — some groups of organisms became extinct, some suffered heavy losses and some appear to have been only minimally affected.

en.wikipedia.org...

As far as other things lurking close by, I'm sure they number in the millions as well. Most think space is just a big empty place, and maybe it is in those areas away from galaxies, but around them, things are quite active. I think of spiral galaxies as I would water going down the drain in a sink, roubd and round and then down and out.

This is pretty interesting.
The idea of an invisible Galaxy boggles my mind.
I wonder what that means exactly. Also, it makes me wonder about how it is going to interact with our own galaxy.

Very odd. Looking forward to reading more about it.
S&F

Bellow is a Wikipedia definition of Dark Galaxy:

A dark galaxy is a galaxy-sized object containing very few or no stars (hence 'dark'). Held together by dark matter, it may also contain gas and dust. No dark galaxy with a black hole as a center has yet been discovered.

The above states that it is all held together by Dark matter and we know very little about dark matter. I wonder if it can disturb the Oort cloud

I am also puzzled by the fact that it can rip through our galaxy without merging with it

Could this be what wiped out previous civilizations that made the pyramids and such. The old civilizations must have left clues.

A dark galaxy, made of dark matter, interesting.

Here's a pretty cool story from '05
~sample

Radio astronomers may have found the first ever galaxy that is made almost entirely of dark matter. The "dark galaxy", which lies in the Virgo cluster about 50 million light years away, rotates in the same way as an ordinary galaxy but does not contain any stars (R Minchin et al. 2005 Astrophys. J. 622 L21-L24).

Dark matter was originally proposed to explain why galaxies rotate much faster than can be explained by the amount of visible matter they contain. This mysterious form of matter does not emit or absorb electromagnetic radiation -- hence the name "dark" -- and can only be detected by its gravitational influence on ordinary matter. Overall the universe is thought to contain about 5% of ordinary matter, 25% of dark matter and 70% of dark energy. Although various types of new particle have been proposed to explain the dark matter, the nature of the dark energy remains a complete mystery.
Physics World.com

Another good story on this subject from '05
~sample

Strong evidence for a massive galaxy totally devoid of stars has been found in the Virgo cluster, about 50 million light years away from Earth. If the existence of this "dark galaxy" is confirmed, it will vindicate the favoured theory of how galaxies form - and will present fresh puzzles to solve.

The new galaxy, which consists of a gigantic cloud of hydrogen gas and exotic dark matter, contains enough material to give birth to tens of millions of stars. Yet something is preventing this from happening. Such dark galaxies have been predicted, and could outnumber normal galaxies by as much as a hundred to one, but this is the first time anyone has confidently claimed to have seen one
New Scientist.com

From the link in the OP

n 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.

It is not specific here but I wonder if this is the same "dark galaxy" that they discovered in Virgo in 2005 and named VIRGOHI21?

Many, many questions. Is there a danger?
Can we even answer that question with certainty?

Good stuff

reply to post by AlienChaser


Thanks for the input AlienChaser. If as you said this is the same Galaxy found in 2005 then this means it has traveled alarmingly fast to hit us.

A very interesting Fact:

Dark matter makes up about 23 percent of the universe's mass-energy budget. Normal matter, the stuff of stars, planets and people, contributes just 4 percent. The rest of the universe is driven by an even more mysterious thing called dark energy.

Based on the above, we can reasonably say that we know very little of surrounds us just about 4%. This is alarming

I bet a lot of scientist will come forward and say not to worry nothing will happen, but then how can they say that when they understand only about 4% of the universe

Space is so confusing.

I would really like to know what dark matter is, and what it does.

reply to post by rattan1


Nice find! I wish the article was more explainitory, you know, for those like myself who don't understand why we can't just look up and see this happening, but, nonetheless, I enjoy knowing.

reply to post by rattan1


Ripping through our galaxy, that statement make me think of Hopi legend, in which they believed earth would birth a 'hidden egg' upon the arrival of the 5th world?

[edit on 22-11-2009 by space cadet]

Originally posted by space cadet
reply to post by rattan1

 

Nice find! I wish the article was more explainitory, you know, for those like myself who don't understand why we can't just look up and see this happening, but, nonetheless, I enjoy knowing.

I also wish there were more explanation in the article. Surely other people like me would be alarmed by this article and more explanation is certainly needed. I am counting on some of the ATS experts here to shed some light on the matter.

The truth is we know nothing about dark matter. The only way to observe it is by the effect it has on known matter such as some galaxies spins faster than they should and by including dark matter in the equation solved the problem.

The article says that it is Dark Matter that is keeping that Galaxy together, therefore, we can conclude that dark matter has gravitational properties and that will certainly affect our own galaxy. Also scientist underestimated the size of that Galaxy.....what else did they underestimate

reply to post by rattan1


Scary but interesting thoughts! Something of this size would surely have a tremendous effect on the galaxy, perhaps this is the reason for the planets that have been reported to be 'wobbling' due to an unseen force

Excellent theory on "dark energy"
~sample

In the early universe, neutrinos would have been packed relatively tightly. Nowadays they are farther apart and so each has greater mass, the new theory suggests. As they move apart, a tension develops between them, like that in a stretched rubber band, said Ann Nelson, a physics professor at the University of Washington.

The increasing tension is the infamous dark energy, explained Neal Weiner, a physicist at the university and another member of the study team.
Space.com

Neutrinos and Sub-Atomic particles?? I should join Starfleet

Cool stuff especially considering that in 2001 Cambrdge university was hosting debates on the existence of dark matter/dark energy, and today we have a dark galaxy crashing into our own.

I am still looking around but I no longer think this impacting galaxy is VIRGOH121 because it was about 50 million light years away when they discovered it in 2005. Also, according to computer simulations there should be hundreds of dwarf galaxies locally, but only 35 have yet been found, so I suspect that as we learn more we will discover many more dark galaxies and energy.

the gravitational effects of the encounter are enough to twist and distort galaxies beyond recognition

Wow. Just, Wow, check out this article from space.com, it is dated 2002, and is explaining what happens when another galaxy crashes into ours, it is using the andromeda galaxy, which is said WILL for sure crash with ours, in a million or more years. Now I am bothered.

edit, sorry I was so excited I forgot to post the link, lol!

www.space.com...

[edit on 22-11-2009 by space cadet]

[edit on 22-11-2009 by space cadet]

Originally posted by Happyfeet
Could this be what wiped out previous civilizations that made the pyramids and such. The old civilizations must have left clues.

well not if it was 70 million years ago. unless you believe that the pyramids are that old. did the article say which part of our galaxy this is happening in? it may not affect this solar system for thousands of years if at all.

Whats more alarming is that EVERY galaxy has a blackhole as its centre. So which part of our galaxy is this occuring. If it was on ourside of the galaxy then theres nothing to stop it from eating us up :p

I alway read the article before checking the date first, alright, so this thing has been crashing into the Milky Way since 2008, January 2008 is when it was first reported to be doing so, only they were only calling it a cloud of gas, what is new is the finding that it is actually another galaxy! The 'smith cloud' as it was refered to, was found back in 1963, only they had no idea it was moving towards us.
Check out this article of the impending collision:www.newscientist.com...

After seeing the colliding galaxies posted earlier, I looked into the effects we might expect from this dark galaxy in the milky way. Luckily, it's not at all the same thing.

It would seam that the dark matter is everywhere.

Prior to this work, it was thought that dark matter forms in roughly spherical lumps called ‘halos’, one of which envelopes the Milky Way. But this ‘standard’ theory is based on supercomputer simulations that model the gravitational influence of the dark matter alone. The new work includes the gravitational influence of the stars and gas that also make up our Galaxy.

Stars and gas are thought to have settled into disks very early on in the life of the Universe and this affected how smaller dark matter halos formed. The team’s results suggest that most lumps of dark matter in our locality merged to form a halo around the Milky Way. But the largest lumps were preferentially dragged towards the galactic disk and were then torn apart, creating a disk of dark matter within the Galaxy.
Physorg.com

The above leads us to the XENON100 detector which should be able to detect dark matter particles right here on Earth.

April 2009: On April 6th, a strong eartquake hit the Abruzzo region where the XENON100 detector is located in the LNGS underground lab, causing the death of several hundred people and dramatic damages to many buildings.

However, we were lucky and no XENON member suffered serious injury. The detector is also fine and we are able to operate it almost as normal.
Xenon100 Rice.edu

Strange that a deadly earthquake just happens to hit the area where the detector is located, but I have concluded there is no conspiracy in it. It is unfortunate so many people died and strange I hadn't heard this on the news. Fortunately the detector was not damaged.

Wired did a good story on the Xenon100 detector on August 6th 2009. It took me a minute to find a copy that was not a pdf but through the power of the internet, I triumphed. This is an excellent 5 pager. Detailing the Xenon 100 and the experiment. This one answers nearly all the questions and I eagerly await the results of the test. Highly recommended!
Wired U.K. on the Xenon 100 experiment

It should be noted that Discover Magazine lists the Xenon dark matter experiment as one of the 6 most important experiments in the world. Funny how I had never heard about it until today

I read that they said our solar system was actually part of the Dwarf Sagitarius Galaxy which crashed into the Milky Way Galaxy a long time ago.
We are, from what I understand on the outer rim, of the Milky Way.
The way they came up with this, not being from MM, is upon looking at the Milky Way, it is turned wrong from our perspective, for our solar system to of been part of it originally.

There are probabily a lot of those dust clouds still out there in the mix, but I guess when the larger more well formed Galaxies crash into each other, brand new stars and solar systems can be formed.