The Earth is constantly bombarded with “micrometeorites.” Fragments of small asteroids and comets. Scientists have determined the typical accretion rate of these particles to be between 20 and 60 million kilograms per year.
That means, on average, more than 100,000 kg falls to Earth every day.
The mass distribution of these particles peaks at about 1.5 × 10-5 grams, and the diameter is about 200 micrometers (1 mm = 1,000 micrometers). Therefore, on average, about 6.7 × 1012 micrometeorites fall to Earth every day.
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If they fell evenly across the Earth’s surface (which is not entirely true), each 75 square meters (807 ft2) of the Earth’s surface would receive one micrometeorite per day.
Assuming these particles fall vertically and the average human head has a diameter of 14.4 cm (5.5 inches), if you stand in the same place for 24 hours, the chance of being hit by a particle is approximately 1 in 4,600. It will be.
In other words, you would have to stand in the same spot for almost 13 years to see if a micrometeorite gets caught in your hair.
Of course, these are just average numbers, and you’re likely to have cosmic dust in your hair at some point while you’re out and about. But it doesn’t happen that often.
This article is in response to the question (asked by Laura Wolfe from County Durham): “Is it true that you get space dust in your hair when you’re outdoors?”
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