How does dust get everywhere?

Question

You go into a room that hasn’t had folks in it for 10 years and there is dust everywhere. I thought it was skin cells but obviously not.

Even rooms with no access to the outside have dust.

In: Mathematics

Answer 1

Estimates are that about 40,000 metric tons of cosmic debris strike earth each year. Many thousands of tons of that end up as dust in the atmosphere. So, space dust is a contributing factor of dust on your fireplace mantle.