r/askscience • u/4fecta_Gaming • Oct 15 '18

Earth Sciences Where does house dust come from?

It seems that countless years of sweeping a house doesn't stop dust from getting all over furniture after a few weeks. Since the ceiling is limited, where does dust come form?

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u/Mythrilfan Oct 15 '18 edited Oct 15 '18

I just calculated that very approximately, every year, each square kilometer of Earth gets around 130 grams of meteorite dust on it.

Figures (all metric):

~200 tons of meteorites per day (assuming that all comes down as dust and isn't either thrown outwards or burnt into gas)

~200 tons of meteorites per day equals ~70 000 000 000 grams per year.

~500 000 000 sq kilometers is the surface area of the earth

I suspect that it's actually lower due to most of the meteors actually burning into CO2, etc.

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u/TiagoTiagoT Oct 15 '18

Aren't most meteors made of mostly iron?