All we are is dust in the interstellar wind

All we are is dust in the interstellar wind
Radio/optical composite of the Orion Molecular Cloud Complex, which includes the Orion Nebula (bottom), featuring a dust-rich star-forming filament called OMC-2/3. Orange: Green Bank Telescope data. Credit: S. Schnee, et al.; B. Saxton, B. Kent (NRAO/AUI/NSF)

Cosmic dust is not simply something to sweep under the rug and forget about.

Instead, NSF-funded astronomers are studying and even mapping it to learn more about what it might be hiding from us, where it comes from and what it's turning into.

Some researchers are delving deep down to see how comes together at the atomic level, while others are looking at the big picture to see where and planets might be forming in dusty stellar nurseries. Recent discoveries, such as that of a very young galaxy containing much more dust than expected, have shown us that we still have much to learn about where exactly all this dust comes from.

A little bit of dust makes a very large problem

Although dust only makes up about 1 percent of the interstellar medium (the stuff between the stars), it can have big effects on astronomical observations. Dust has a bad reputation because it gets in the way by absorbing and scattering the visible light from objects such as far-off galaxies and stars, making them difficult or impossible to observe with optical telescopes.

The scattering effect dust has is known as "reddening"—dust scatters the blue light coming from an object, making it appear redder. This occurs because dust has a greater effect on light with short wavelengths, such as blue. A similar effect is what causes sunsets to appear red.

Astronomers can tell a lot about a star simply by its color, so this reddening effect can trick us into thinking a star is cooler and dimmer than it actually is. However, thanks to NSF-funded astronomers like Doug Finkbeiner of the Harvard-Smithsonian Center for Astrophysics, we can now correct for dust reddening and recover a star's intrinsic color.

Finkbeiner first began studying as a graduate student at the University of California, Berkeley in the late 1990s. Dust may seem like an odd thing to dedicate an astronomical career to but "dust is not as obscure as it sounds," Finkbeiner said. "Objects like the Orion Nebula, the Horsehead Nebula, and the Pillars of Creation are dense, dusty clouds intermingled with bright stars, making a beautiful scene. But every part of the sky has at least some dust, and even a tiny amount of dust can interfere with astronomical measurements, so we need a way to correct for it."

A necessary nuisance

Knowing where dust is, and where it isn't, gives us a better understanding of what's happening in our galaxy. For example, an area saturated with dust may indicate a hotbed of star formation activity, while holes in an otherwise dusty area tell us that a supernova may have occurred and blown a pocket of dust away.

"Dust is not a very glamorous name for something this important," said Glen Langston, an NSF astronomy program director. "It represents both sides of star life—star birth and star death."

These dusty areas are also factories of cosmic chemistry—chemistry that creates molecules such as graphite (otherwise known as the stuff inside your pencil).

When dying stars explode, they expel dust out into space that can be recycled to make something new. In fact, everything in the universe—stars, comets, asteroids, planets, even humans, started out as grains of dust floating around in space. As the late astronomer Carl Sagan famously said, "The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff."

Astronomers can peer into the galaxy and tell that some stars are making dust right now, but other dust might be billions of years old with a long, complicated history of growing, shrinking, freezing and burning as it traveled through space.

"It's not a bad analogy to think of dust like grains of sand on the beach," Finkbeiner said. "You might have sand that looks the same because it's coming from a coral reef 100 meters away, but in other places you might have sand that came from very far away which has been through a lot over thousands or millions of years."

Set your course by the stars...or dust

Using data from almost one billion stars, Finkbeiner, along with student Gregory Green and former student Edward Schlafly, created a 3-D map of reddening across three quarters of the visible sky. This map allows astronomers to know when the targets of their observations may be suffering a reddening effect, and how much reddening they can expect. (You can further explore our dusty galaxy through several videos on a website Green created.)

Dust distribution reveals our galaxy's structure and we can see that most of the dust is contained in the disk, which is the plane in which the spiral arms of our galaxy lie. It also provides a snapshot of our galaxy's history, showing that the Milky Way has had its fair share of galactic fender benders with other galaxies. In fact, we are due to collide and merge with our neighbor, the Andromeda galaxy, in about 4 billion years.

Like dents in a bumper, we can see the damage by looking for ghostly trails of dust extending outward from the disk, showing that another galaxy might have passed through, dragging dust from our galaxy along for the ride.

The map already combines data from 2MASS (the Two Micron All Sky Survey) and Pan-STARRS 1 (the Panoramic Survey Telescope & Rapid Response System), but there's still a long way to go. Using multiple telescopes, 2MASS surveyed the entire sky in three infrared wavelengths between 1997 and 2001, while Pan-STARRS observes the entire visible sky several times per month. Pan-STARRS has provided a lot of data, but it is a drop in the bucket compared to what's on the horizon.

A few years from now, DECam (the Dark Energy Camera), a sensitive wide-field camera attached to the 4-meter Victor M. Blanco Telescope, will have looked at the entire southern hemisphere, allowing Finkbeiner to update his map to include the full sky in detail. In the 2020s, LSST (the Large Synoptic Survey Telescope)—a wide-field telescope with an 8.4-meter primary mirror and the largest digital camera ever constructed—will provide data for 10 times more stars than currently available, recording the entire visible sky twice every week.

LSST will gather more than 30 terabytes of data every night, providing more data than ever before. Astronomers like Finkbeiner are excited to face the new challenges this data overload will bring, hoping to solve some of the greatest cosmic mysteries, including the origin of some of the universe's oldest dust. LSST, DECam, and several other surveys combined will help create a new map of much higher detail.

In the future, Finkbeiner hopes his map will be incorporated with WorldWide Telescope, a free community-driven computer program that gathers the best images from ground and space-based telescopes and combines them with 3D navigation.

"I can imagine the final product as something very beautiful," Finkbeiner said. "So beautiful that every Hollywood movie will want to use it for their flying-through-the-galaxy scenes."

Explore further

Image: Hubble's diamond in the dust

Citation: All we are is dust in the interstellar wind (2016, March 9) retrieved 22 July 2019 from
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Mar 09, 2016
Ashes to ashes, dust to dust....the answer is blow'in in the wind.

Mar 10, 2016
It's called a Complex Plasma, there you go, your better alternative to 'Dust'.

Having said that, I wonder if this 'reddening' is throwing off distance measurements that rely on 'doppler redshift'? Maybe the universe isn't as vast as supposed?

Mar 10, 2016
P.S. this is the same dust that fudged the gravity wave discovery last year, as there is vastly more than they had previously believed.

Mar 10, 2016
I believe any attempts to measure the universe are "Half-Vast" (say it quickly, over and over). Never attempt to make vast estimates with half-vast data and measurements.

Mar 10, 2016

William Blake (200 years ago)

"To See a World..."

(Fragments from "Auguries of Innocence"
To see a World in a Grain of Sand
And a Heaven in a Wild Flower,
Hold Infinity in the palm of your hand
And Eternity in an hour.

We have only begun to see the wonders of Creation with our feeble attempts to measure the universe.

Mar 10, 2016
It's called a Complex Plasma

How about: No?
I wonder if this 'reddening' is throwing off distance measurements that rely on 'doppler redshift'?

No. Dust does not change spectral line positions. Redshift does.

Mar 10, 2016
Why do you say no?

And good point about my redshift question.

Wenkl2 check out the song Heaven in a Wild Flower by Bill Douglas

Mar 10, 2016
I used Blake's quote many years in physical science classes and the students just exclaimed "HUH?" I made it an extra credit question on final exams if they could make the connection to silica dioxide and grains to beaches of sand. Even the computers which process all the information and create the images we see in this article rely on silicon for the computer chips. And we studied outdoors on the Pacific Coast! After this cosmic dust article, they would get it. I never have felt more confident in the awesome unity of the Creation than after the recent links of scientific research to the "Music of the Spheres" and the commonalities we share with every planet, meteor, and asteroid we study. I have to believe there was a Plan to all this, an Intelligent Design behind all of the universe.

Mar 10, 2016
"Heaven In A Wildflower " sounds like a Willy Nelson tune, is that Bill Douglas singing? Willie and I go back a long ways to the 60's and he would be proud to sing it! Since I am in CO up at 9400 feet , above and southwest of Denver, I have the Rocky Mountain High every day ,( just almost as good as Willy does in Texas!)

Mar 10, 2016
Wenkl2 you sound like an interesting individual, a mind worth picking.

Mar 10, 2016
How can it possibly make up about 1% of the interstellar medium? If that is true how could we even look out beyond our galaxy?

Quote from article:
"Although dust only makes up about 1 percent of the interstellar medium (the stuff between the stars), it can have big effects on astronomical observations. Dust has a bad reputation because it gets in the way by absorbing and scattering the visible light from objects such as far-off galaxies and stars, making them difficult or impossible to observe with optical telescopes."

Mar 10, 2016
You probably don't believe in a lot of things, including the Heisenberg principle. Uncertainty is the root of Physics and physics teachers are skeptical of everything, including their own theories. I don't doubt your credentials, I just know that I believe in the scientific method for gaining an understanding of the world around us. But science has limitations and humans will fail to maintain objectivity and are easily swayed by the latest and greatest popular interpretations of information. Look at the current Scientific American. What used to be an objective publication of research findings and has become a pop sci tabloid. Researchers are publishing findings in magazines to compete for shelf space at the grocery! Juried professional science journals are having to sell ads that make the interpretations of research biased toward the advertisers who support the publications. No wonder the classical physics is lacking. If it does not explode or change colors, make bubbles it gets cut.,

Mar 11, 2016
Wenkl2 shoot me an email at Yahoo


Mar 11, 2016
If that "dust" is about 70% H2O, then I'm a believer.

Mar 11, 2016
Hi antialias_phys. :)
Dust does not change spectral line positions. Redshift does.
Can't stay, so just a brief observation, mate.
The line-of-sight to any obect is full of clouds/material being attracted towards gravitating bodies. Once the light transitions those gravitational wells, the NEAR side material (accelerated away from us, towards the gravitating body) imprint the last material-related redshifting on said transiting light. It is not only the 'fog effect' which reddens due to absorbing/refracting bluer wavelengths, it is ALSO the RECESSION velocity of the 'near surface of last scattering' of such clouds which redshifts ALL frequencies being re-emitted by relaxing ions/molecules. So the e-m 'signals' we 'see' are not as cut and dried as to 'shift-causes' as the old one-way-fits-all 'fog reddening' assumptions would have us believe. Anyhow, can't stay. Good luck in discussion. Cheers. :)

PS: Far side clouds effects would be obscured by near side clouds.

Mar 11, 2016
I do not believe that you teach physics.
Don't feel bad about that Phys-Skippy. Nobody believed he was a nurse or NASA engineer or black psychiatrist or NSA spy or any of the hundreds of other things he's been since he's been here. It's one of obama-sock-Skippy's puppets.

Oh yeah, I almost forget. The Skippy writing to him up there? That's him too.

Mar 13, 2016
All we are is dust in the interstellar wind?

Right! That's like saying computers are nothing more than chunks of metal and plastic!

Gotta love that logic!

Mar 13, 2016
You'd figure: Dust; solid particles electrically neutral (or statically charged), Plasma; a gas electrically charged, so it's actually hard to determine what they ever mean at first glance.

Mar 13, 2016
"All we are is dust in the interstellar wind".

No for sure.
This planet was created from water and reorganization of the bilding block of water molecules in another chemical elements by the will and speech of the Creator who control the structure of the vacuum of space. Or with other words by reprogramming of the physical environment.

Mar 13, 2016
Why do you say no?

Because I checked around for publications by the guy cited in the article and it's always about "dust grains" - i.e. not plasma. In some publications he specifically studies interactions of (rotating) dust grains with plasma.

Mar 13, 2016
This is only half of it.

We will all return to the nothingness of dust again.

Mar 13, 2016
We will all return to the nothingness of dust again
We know that you try to be human. It must be a real strain on you.

"The study of "ambulatory" psychopaths - what we call "The Garden Variety Psychopath" - has, however, hardly begun. Very little is known about subcriminal psychopathy... it is important to study psychopathy not as an artificial clinical category but as a general personality trait in the community at large... as a more or less a different type of human.

"What distinguishes all of these people from the rest of us is an utterly empty hole in the psyche, where there should be the most evolved of all humanizing functions.

"the psychopath has a regular need to take a "vacation into filth and degradation" the same way normal people may take a vacation to a resort where they enjoy beautiful surroundings and culture. To get a full feeling for this strange "need"... evidence that "acting human" is very stressful to the psychopath."

Poor baby.

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