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  • Meet Dermatophagoides farinae.

  • Crawling around on eight legs, this creature has no eyes to appreciate the kaleidoscope of colors around her.

  • She relies on her extraordinary sense of smell to lead her to food and safe places to lay eggs.

  • And she's smaller than a pinhead.

  • Dermatophagoides farinae is a dust mite.

  • Less than a tenth the size of an ant, a dust mite's whole world is contained in the dusty film under a bed or in a forgotten corner.

  • This realm is right under our noses, but from our perspective, the tiny specks of brilliant color blend together into a nondescript grey.

  • What are these colorful microscopic particles?

  • What distinguishes the dust in your house from, say, sand on a beach is that it is a mixture of many different ingredients.

  • It can contain grains of sand, dead skin cells, tiny hairs and threads, animal dander, pollen, man-made pollutants, minerals from outer space, and, of course, dust mites.

  • Dust mites eat animal dander, human skin, and some fungi.

  • We shed dead skin cells constantly, and wherever we live, they mix into the household dust.

  • The same goes for our pets: their dander and hairs enter the mix, as do tiny pieces of thread and cotton fibers from our clothes.

  • 'These components make every household's dust a unique blend of bits from its particular inhabitants.

  • Household dust also contains substances that blow in from the wider world.

  • Depending on the local geology, finely ground quartz, coal, or volcanic ash might enter the air as atmospheric dust, along with pollen and fungal spores.

  • Industrial activities also contribute cement powder, particles from car tires, and other chemicals to the airborne mix.

  • The combination of these elements can be as unique as a fingerprint.

  • In Spain, where the land is rich in carbonate materials, dust contains 20 times as much calcium as dust in Nigeria, where the geology is quite different.

  • After a particularly violent storm, scientists identified dust from the Sahara Desert thousands of miles away in London, based on its specific composition.

  • In the future, we may be able to pinpoint the origins of dust samples even more specifically, down to a particular neighborhood or even housesomething that may be of great help for forensic specialists.

  • In addition to markers of humans, animals, and landscapes, dust also contains particles from further afield.

  • When a star explodes in a distant galaxy, super hot gases vaporize everything nearby.

  • Then, the dust settles; minerals condense out of the gas.

  • Floating out there between planets and galaxies, this extraterrestrial dust contains tiny pieces of extinguished stars and the building blocks of future celestial bodies.

  • Every year, tens of thousands of tons of cosmic dust lands on Earth and mingles with terrestrial minerals.

  • This blend of chemicals, minerals, and intergalactic particles settles out of the air onto surfaces in our homes, mixing with the detritus of each house's occupants.

  • Stars explode, mountains erode, and buildings, plants, and animals are all slowly but surely pulverized into fine grey powder.

  • We're all destined to become dust, but it's also possible that we came from it.

  • Interstellar dust has been found to carry organic compounds through space.

  • It's possible that billions of years ago, some of these cosmic particles were the seed of life on our little blue planet.

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Meet Dermatophagoides farinae.

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What is dust made of? - Michael Marder

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    April Lu posted on 2019/01/05
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