How many meteorites land on Earth every day?
Scientists estimate that dozens to hundreds of meteorites heavier than about 10 grams land somewhere on Earth every day, mostly in the sea or in places where nobody sees them.
Space rocks are landing on Earth all the time, every single day.
Scientists use cameras that watch the sky to count bright fireballs, and from these counts they estimate how many meteorites reach the ground. Their estimates suggest that tens of thousands of meteorites heavier than about 10 grams, about the weight of two sugar cubes, land on Earth every year. That works out at dozens to hundreds every day!
As well as these, thousands of tonnes of tiny space dust, too small to see, drift down every year.
So why don't we find them all? Here are the reasons:
- About seven-tenths of Earth is covered by ocean, so most meteorites splash into the sea. - Much of the land is forest, mountains, deserts or ice, where few people live. - Most meteorites are small and dark and look like ordinary stones. - Many fall at night, or in cloudy weather, when nobody sees them.
That is why only a few meteorite falls are seen and collected each year around the world. In Britain, a fall is found only every few decades. But they are out there! Every time you go for a walk in the countryside, there is a tiny chance a meteorite is lying somewhere nearby.