Planck Mission Releases Images of Galactic Dust 40
davecl writes "The Planck satellite has released its first new science images, showing the large scale filamentary structure of cold dust in our own galaxy. This release coincides with the completion of its first survey of the entire sky a couple of weeks ago. There's lots more work to be done, and more observations to be made, before results are ready on the Big Bang, but these images demonstrate Planck's performance and capability. More information is available on the Planck mission blog (which I maintain)."
Size? (Score:3, Insightful)
When talking about things at the galaxy scale, what is considered dust? Is this actual real "dust" of the size that collects on my shelves, grains of sand sized bits, gravel, or something larger?
Re:Size? (Score:5, Informative)
When talking about things at the galaxy scale, what is considered dust? Is this actual real "dust" of the size that collects on my shelves, grains of sand sized bits, gravel, or something larger?
The phrase to google for is "cosmic dust"
You'll be displeased with the answer, it seems to be a very wide range of stuff from two molecules having a public display of affection all the way up to the low end of vaguely sand-like.
I don't really know what collects on your shelves, but "cosmic dust" is probably vaguely similar.
This sand and gravel stuff you talk about, is by definition a "meteor".
http://en.wikipedia.org/wiki/Cosmic_dust [wikipedia.org]
http://en.wikipedia.org/wiki/Meteor [wikipedia.org]
Re: (Score:2, Informative)
It's also pretty thinned out, often where it takes light years' worth of a "cloud" of it to finally provide enough coverage to 100% block out the stars behind it.
Re:Size? (Score:4, Informative)
Re: (Score:2)
So, umm... with all that dust out there, is it possible that light could be attenuating between here and the perceived "edge" of the universe? Couldn't the presence of large amounts of dust mean that our universe is larger than current estimates?
Think of it like your headlights on a dark night... the further away you get the more light disperses. Since there's less stuff in space to disperse light, we can see for X billion light years, but the presence of dust could be masking a large portion of visible s
Re:Size? (Score:4, Informative)
So, umm... with all that dust out there, is it possible that light could be attenuating between here and the perceived "edge" of the universe? Couldn't the presence of large amounts of dust mean that our universe is larger than current estimates?
Think of it like your headlights on a dark night... the further away you get the more light disperses. Since there's less stuff in space to disperse light, we can see for X billion light years, but the presence of dust could be masking a large portion of visible space in this manner. I would assume this would have to happen, otherwise space would be white with light instead of black, right?
It's well known that there's a lot of dust, that doesn't hurt our understanding of the size of the observable universe. It might increase our error bars a little in the first few steps of the distance ladder (http://en.wikipedia.org/wiki/Distance_ladder), but probably not significantly. Dust isn't an effective absorber of every wavelength of light, so we can see through it if we want.
If you really want to get a good handle on this rather complex and fascinating topic, read the above article and the less awesome but still useful article on the size of the observable universe (http://en.wikipedia.org/wiki/Size_of_the_universe).
Re: (Score:2, Informative)
"Couldn't the presence of large amounts of dust mean that our universe is larger than current estimates?"
No, because current measurement of the size of the observable universe is not based on brightness but is based on redshift.
Re: (Score:1)
No, because current measurement of the size of the observable universe is not based on brightness but is based on redshift.
Which brings us right on back, circularly, to "Couldn't the presence of large amounts of dust mean that our universe is larger than current estimates?"
I'm just saying, dust probably comes along with a free order of hydrogen gas clouds, the spectrum of which might be redshifted at a velocity that has nothing to do with the galaxies/stars behind them.
My wild guess, to work around that problem, would be to watch redshift and light curve of supernovas in distant galaxies...
Re: (Score:1)
Re: (Score:2)
It ... doesn't work that way. If you care about this subject (and it seems like you do), you might find it entertaining to read up on at least the very basics [wikipedia.org], as might be found in Wikipedia.
Re:Size? (Score:5, Informative)
APOD has a good description and picture (well, computer-generated visualization) of dust:
By studying how dust absorbs, emits, and reflects light, astronomers do know that interstellar dust is much different than the cell and lint based dust found around a typical house. Interstellar dust grains are composed mostly of carbon, silicon, and oxygen and are usually less than about 1/1000 of a millimeter across. Recent work indicates that most dust grains are not spherical. The above picture shows the result of a fractal adhesion model for dust grains involving random conglomerates of spherical compounds of different properties, here artificially highlighted by different colors.
(from http://apod.nasa.gov/apod/ap961119.html [nasa.gov])
Re: (Score:2)
Whatever it is one thing is for certain, the galaxy is filthy. No wonder I'm always sneezing.
That's no dust cloud (Score:3, Funny)
Best call the Fantastic Four, it sounds like we're about to receive a visit from the Silver Surfer [wikipedia.org]
High-Res? (Score:2, Interesting)
Re:High-Res? (Score:4, Informative)
They consider 1000x892 pixels high resolution? Last I checked, that was high res circa 1995..
For marketing / PR / Journalist folks that is high-enough res... it'll look OK on a HDTV, a web page, or in a 100 dpi B/W newspaper. They call it a "press" release for a reason, not a science release or a data release.
If you want 2000x1500 or whatever, I think you're asking for the science data, which is not released yet. Usually the way it works with space probes is the folks whom ran it keep the data to themselves for "awhile" before its released to the public. Usually "about a year". No idea how it works with Planck, couldn't even google it.
Since the public doesn't really care (just being honest here) I think the main purpose of early press releases is to intimidate the researchers whom aren't in the inner circle whom have actual data.
I did find a nice description of the HFI "imager" device... Its resolution is about 5 arc minutes depending on frequency, etc.
Your eyes resolution is about 1 arc minute. So, the output of the HFI would be a slightly blurry version of what your eyes see, sort of. Just drink a few beers and drop some acid and look at the stars and you'll be pretty much on your way.
I did not bother researching the other instruments on Planck. Someone with more motivation can do that and gain the karma.
http://xxx.lanl.gov/ftp/astro-ph/papers/0308/0308075.pdf [lanl.gov]
http://en.wikipedia.org/wiki/Visual_acuity [wikipedia.org]
Re: (Score:1, Funny)
Ooock Imm don, shtooned like heeeeell! And I see shchmurfs jumpinn outta my windowss, cuz i took the acid too, ya now? But, can't find the shtars you talkin' about. Schmurf says its 3 pmm, i flucked something up?
Re: (Score:3, Funny)
I did find a nice description of the HFI "imager" device... Its resolution is about 5 arc minutes depending on frequency, etc.
Not bad for the smallest telescope possible!
Huge waste of money (Score:4, Insightful)
Re: (Score:2)
They said dust, not life forms.
Re: (Score:1, Funny)
...not life forms.
Specifically, gametes.
Yeah, no. No one is looking for that.
Re: (Score:2)
Re: (Score:1)
And back to dust, full circle!
> (Score:2, Troll)
>
> If they wanted pictures of dust, they could have just photographed under my bed!
Troll? If a particularly Angela-esque person wanted to slam a humor post, go ahead, but at least use "off topic".
Unless...unless it hit too close to home? But then the nerds/sex issue should really send this person into a tizzy.
Where is Mega Maid? (Score:2)
I mean, you'd think the break-out-galactic-pledge department would have her on speed dial or something.
Re: (Score:2, Funny)
They do -- that's prolly why she stopped returning calls.
A nice picture (Score:1, Redundant)
Here is a nice picture of plank:
http://beansie09.tripod.com/sitebuildercontent/sitebuilderpictures/plank.jpg [tripod.com]
Nice try (Score:4, Informative)
Re: (Score:1)
Nice picture. Oh,look! It's held together with masking tape!
Re: (Score:2)
Re:A nice picture (Score:4, Funny)
Wow! It looks just like the hosted by tripod logo!
Fractals! (Score:3, Interesting)
FTA: One puzzle to be solved is why there is similar filamentary structure on both the large and the small scale. "That's a big question," says Tauber.
Interesting that these filaments could probably be modeled using fractals. http://en.wikipedia.org/wiki/Fractal [wikipedia.org]
Constant Value For Dust (Score:2, Funny)
Looks like Vernor Vinge's "Zones" (Score:4, Interesting)
In Vernor Vinge's fantastic book "A Fire Upon The Deep", he postulates the existence of "Zones" where variations in cosmic constants(?) allow increasingly sophisticated intelligences (and corresponding FTL travel). We (earth) live in the "Slow Zone" where only human level intelligence is possible.
Anyway these pictures, with their galactic scale structures showing Fractal like properties, reminds me of that!
By the way, the book really is awesome (Hugo and Nebula winner) just about the best SF I've read along with Stanislaw Lem's "Imaginary Magnitude". If you're a slashdot geek (and aren't we all?) you'll love his galactic Internet (he's a computer science professor). Oh, and he is credited with the idea of the "Singularity".
Re: (Score:2)
I always found that zones thing such a weird aspect of that book. On the one hand I found it so strange and, really, unscientific, that I didn't know whether to consider it stupid or silly. On the other hand I thought it made a really, really cool plot device. That was enough to make me want to read more books featuring this idea, but I don't know if he ever wrote any?
Btw, I thought Kurtzweil was credited with the Singularity?
Re: (Score:1)
That was enough to make me want to read more books featuring this idea, but I don't know if he ever wrote any?
"A Deepness in the Sky" is set in the same universe, but if I remember correctly the whole books takes place in the slow zone.
Re: (Score:1)
Vinge has admitted it was a way to basically get around what he sees as inevitable -- the coming of the Singularity, and probably well before there is any interstellar, much less intergalactic, travel.
Hence he has no real way to write stories set in classic sci-fi space, with alien races and rockets and FTL ships and what-not. It will never be that way.
Zones was a way to get around what he sees as (and I agree with) an inevitable end stage for humanity, and not really too far in the future.
Anybody? No? Dust. (Score:1)
Book Scanning (Score:1, Interesting)
This looks like someone simply scanned the cover from a 1970's science fiction paperback. It's beautiful on many levels.
Re: (Score:1)
Too bad it doesn't look like the cover of some bad '70s erotica pulp fiction. "Women's Prison", et al.
Breakdown (Score:2)
Disclaimer: This is from my personal, anecdotal experience. YMWV...
-Microsoft Security Essentials is the current weapon of choice for people too stingy to pay for protection. It does a good job though, and like has been reiterated many times over, it's pretty light on system resources, it doesn't nag unless you have a virus (though it will give you a "yellow signal" if your Windows Update patches aren't current), and it's straightforward in the event the end user actually has to do anything in it.
-Avast is