Unveiling the Mysteries of Dust: Composition, Properties and More

In summary: According to the Astronomical and Astrophysics Encyclopedia, stellar dust is composed of small solid particles, such as amorphous silicate and carbon, that were created during the formation of elements. This dust is found in interstellar space and can also be found in comets and asteroids. Its properties vary depending on its composition and can range from fine grains of minerals to small crystals. It is also known to contain elements and compounds that can be found on Earth.
  • #1
anonymoussome
59
0
What is ...Dust?

I know this is quite ackward and may not be the right place to ask such a question but I am a bit curious to know something good about it:
Earth is composed of soil;
Soil is a mixture of elements and compounds;
But we don't use the soil around us to extract those compounds and use them in lab, neither do we pay much importance to it;

Then comes dust;
pretty much the same story.
So the thing we call dust:
What is its atomic number and properties.




Then comes the last question
What is stellar dust, its composition, properties etc.?
 
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  • #2
I do not think that what people on Earth call "dust" is very well defined. Whether you live in China near a coal fired power station or, say, somewhere in the countryside in the US should result in a completely different kind of "dust".

As for stellar dust, a short qoute from the "Astronomy and Astrophysics Encyclopedia",1992:

"...small solid particles, called dust grains. The composition of these grains is not completely certain, but there appear at least two main types: One type is amorphous silicate and the other is some form of carbon"
 
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  • #3
anonymoussome said:
Earth is composed of soil;
Soil is a mixture of elements and compounds;
But we don't use the soil around us to extract those compounds and use them in lab, neither do we pay much importance to it;
Sometimes, we do exactly that! One of the simpler examples is panning for gold.
Then comes dust;
pretty much the same story.
So the thing we call dust:
What is its atomic number and properties.
Well, household dust is composed mostly of human skin and hair, plus a little pollen, mold, and dead bug parts.
 
  • #4
russ_watters said:
Well, household dust is composed mostly of human skin and hair, plus a little pollen, mold, and dead bug parts.

*barf* :yuck: - maybe we should focus on stellar (or interstellar ?) dust :biggrin:
 
  • #5
russ_watters said:
Sometimes, we do exactly that! One of the simpler examples is panning for gold. Well, household dust is composed mostly of human skin and hair, plus a little pollen, mold, and dead bug parts.
Not to mention, hair/fur from pets, and fibers from carpet, clothes, upholstery, linens, or basically any fabric. One might find dust from the yard or garden.

In interstellar space, dust if fine grains of minerals from way back when elements were formed. If one looks at polycrystalline metals and minerals, one will see small crystals of about 1 micron, with distribution from nm's to a few micrcons. Dust can come from rocks as the result of collisions, and with successive high speed collisions in space with little or no gravity to collect rocks and dust into a planet, the dust particles get smaller and smaller.

Here is some information -

http://www-ssg.sr.unh.edu/ism/what1.html#dust

http://science.nasa.gov/headlines/y2000/ast24apr_1.htm [Broken]

http://stardust.jpl.nasa.gov/home/index.html
 
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  • #6
russ_watters said:
Well, household dust is composed mostly of human skin and hair, plus a little pollen, mold, and dead bug parts.

Thats an old urban myth - most of house dust is geological,quite a lot of it is the sahara.

The nasty stuff does predominate in things like beds and pillows though! Or if you have pets.
 
  • #7
It all depends on what kind of dust you mean. If you are talking about atmospheric dust, then mgb_phys is correct in that much of the dust is geologic in nature, it being made of soil carried up from the wind, particles from volcanic eruptions, and pollution, for a few examples. There are also airborne dusts such as aerosol particles. Likewise, there is coal dust, which has the great potential to cause diseases of the lungs, such as Pneumoconiosis. There is also lunar dust, of the moon, obviously. There is also stellar dust, of which less is known about, but this also depends on specifically what sample one looks at. Currently, the Japanese spacecraft , Hayabusa, is on a mission to collect dust from an asteroid. However, domestic dust really is made out of "human skin cells, plant pollen, human and animal hairs, textile fibers, paper fibers, minerals from outdoor soil and dust, and many other materials which may be found in the local environment." (Kathleen Hess-Kosa, (2002), Indoor Air Quality: sampling methodologies, page 216. CRC Press.) However, this list is not exclusive as the exact composition can vary widely.

Just some fun facts: nearly 1000 dust particles per square centimeter settle on domestic surfaces every hour (same source as before). Also, some dust consists of human skin; it is estimated that the entire outer layer of skin is shed every day or two at a rate of 7 million skin flakes per minute, which corresponds to a mass emission rate of about 20 mg/minute (Heinsohn, R., Cimbala, J., (2003) Indoor Air Quality Engineering: Environmental Health and Control of Indoor Pollutants. page 146. CRC Press.).
 
  • #8
Exploding star debris mixed with primordial matter is the short answer.
 

1. What is dust and where does it come from?

Dust is a collection of small particles that are found in the air or on surfaces. These particles can come from a variety of sources, such as soil erosion, volcanic eruptions, and human activities like burning fossil fuels or smoking. Dust can also be made up of organic materials like pollen, skin cells, and bacteria.

2. What is the composition of dust?

The composition of dust can vary greatly depending on its source. Generally, dust is made up of a combination of minerals, organic matter, and other particles. Some of the most common minerals found in dust include quartz, feldspar, and mica. Organic matter in dust can come from plants, animals, or human activities. Additionally, dust can contain pollutants like heavy metals, pesticides, and microplastics.

3. How does dust affect human health?

Dust can have both short-term and long-term effects on human health. In the short term, exposure to dust can cause respiratory irritation, coughing, and sneezing. Long-term exposure to dust, especially fine particles, has been linked to respiratory diseases, heart disease, and even cancer. Dust can also exacerbate existing health conditions like asthma and allergies.

4. How does dust impact the environment?

Dust can have a significant impact on the environment, both locally and globally. Locally, dust can affect air quality and visibility. It can also deposit on plants and bodies of water, potentially causing harm to the ecosystem. Globally, dust can contribute to climate change by reflecting or absorbing sunlight, altering rainfall patterns, and transporting pollutants and nutrients across long distances.

5. Can dust be beneficial?

While dust is often seen as a nuisance, it can also have some benefits. Dust plays a crucial role in the formation of clouds and precipitation. It also carries nutrients, such as phosphorus and iron, that can fertilize plants and support marine life. Some types of dust, like diatomaceous earth, have industrial uses and can be used as a natural insecticide.

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