How does dust form?

Question

I am wondering why and how it does.

Answer 1

Since you asked this question in earth sciences and geology category, I will assume that you are interested in the kind of dust that gets blown around in the wind, and so forth.
The great volume of this dust is formed by erosion (water, wind, ice) of soil, lake beds, and rocks. Clay particles are an especially abundant component of dust--because of they can be small enough to be easily picked up by wind. But, dust can also contain anything else of the right size (small, light). USGS analysis of dust samples collected at monitoring stations shows that the African dusts can carry pesticides, heavy metals (such as mercury and arsenic), naturally occurring radioactive isotopes, pollen, insects, miscellaneous organic debris, smoke, and pathogenic viruses, bacteria, and fungi.
Arid environments generate big dust clouds at time because there are not many plants holding the surface down. Africa and the dry parts of China, for example, may generate big plumes of dust. Known dust sources in the SW USA include dry lake (playa) surfaces and their margins, ephemeral drainage areas, poorly vegetated alluvial fans, agricultural fields, military bases, and growing urban and rural areas.

http://esp.cr.usgs.gov/info/dust/
http://health.usgs.gov/inhalation/african_dust.html
http://esp.cr.usgs.gov/info/sw/monitor/dust.html

Answer 2

How Does Dust Form

Answer 3

What kind of dust are you asking about?

Dust formation in atmospheres of AGB stars
Temperature low high enough to make molecules stick together
Density high enough to allow frequent collisions of molecules
http://www.astro.uu.se/~bf/publications/2003_10_Lund_AD/dust.htm

Dust can be found anywhere: in the kitchen, in the car, in space… Not surprisingly we
also see dust in commercial and laboratory plasmas. Dust can be introduced in the
plasma, but it can also grow there by itself. In the microelectronics industry,
contamination of the processing plasma by dust is an unacceptable phenomenon.
People have put a lot of effort fighting the dust formation in plasmas. However, recent
discoveries have proven that particles can also be used in the production of more
efficient and stable solar cells and in single electron microelectronics devices.
Particles that are used there have crystalline structure and a typical size of several
nanometres. Since visible light has a wavelength of more than 400 nanometres, these
particles cannot be detected optically; hence, new diagnostics are needed. In most
cases, the active gas used in the discharges is silane – SiH4. This work is devoted to
the study of the particle formation in silane containing plasmas.
The commonly accepted mechanism of dust formation in a low-pressure silane plasma
consists of several stages. First, silane radicals produce crystallite clusters of several
nanometres in diameter. These clusters, when they reach a critical concentration,
approximately equal to the concentration of ions in the plasma, start to agglomerate to
form particles of 20 – 50 nm. These bigger dust formations no longer possess the
crystallite structure of the initial clusters. All further growth is happening on the
surface of the agglomerates.
http://www.phys.tue.nl/EPG/epghome/papers/phd/Sorokin.pdf

Answer 4

Dust is made up of mostly Human dry skin.

Answer 5

what i learned in 6th grade, is it is rom dead skin, and it is dead skin cells. if you stand in front of a window like where you can see the dust in the air, scratch your arm, and you can actually see it leave your arm.

Answer 6

whoever said dry skin is a cotton headed ninnimugins. everyone knows it's little infectious bugs that hunger for sweat. i no it's kinda disgusting but theres nothin we can do about it.