Is there space dust in my house?
Very probably, a tiny amount. Thousands of tonnes of space dust land on Earth every year, and a few grains could settle anywhere, even on your windowsill.
Here is an amazing fact: tiny pieces of space dust are falling on Earth all the time, day and night. Scientists estimate that thousands of tonnes land every year, most of it as grains smaller than a grain of sand. These grains are called micrometeorites.
Most of this dust slows down gently high in the air without burning up completely, then drifts slowly down. It lands everywhere: on oceans, deserts, forests, cities and rooftops. So a few grains of space dust have very probably landed on your house, and perhaps even drifted in through a window.
Finding them is the tricky part, because they are mixed with ordinary dust from soil, plants, pollen, cars and factories. Scientists hunt for them in clean places such as the ice of Antarctica. In 2016, researchers showed that real micrometeorites can be found in the dust collected from city rooftop gutters, using microscopes and careful testing.
Many micrometeorites that melted on the way down are tiny round balls, like miniature marbles, often less than half a millimetre across. You would need a microscope to see them properly. It is a wonderful thought that, somewhere in the dust around you, there may be a speck from space.