Why don't we feel space dust falling on us?
Space dust grains are so tiny and fall so slowly after slowing down high in the air that they land as gently as ordinary dust.
Thousands of tonnes of space dust fall on Earth every year, so you might wonder why you never feel it.
Here is the answer. The dust grains are incredibly small, most of them thinner than a human hair. When they rush into Earth's air from space, the air slows them down very quickly, high above the ground. After that, they drift down slowly, like ordinary dust floating in a sunbeam. It can take days, weeks or even longer for a grain to settle.
By the time a grain reaches the ground, it is moving so gently that you could never feel it landing on you. It would be like feeling a single speck of flour drifting onto your arm.
Also, space dust is spread out over the whole Earth. Even though thousands of tonnes land each year, the planet is so big that only a tiny amount lands on any one square metre, perhaps a few grains a year in each square metre.
Scientists collect this dust in special places, like the clean snow of Antarctica, or high in the sky using aeroplanes with sticky collectors. They have even found space dust in rain gutters on city roofs. So space dust is all around us, but it lands so softly that we never notice.