The vast majority of these iron and nickel-rich particles come from comets and transiting asteroids, but these particles do not pose a threat to our world.
These tiny meteorites, as is known, are very small, from a few tenths to hundreds of parts of a millimeter.
The researchers said their understanding could provide insight into the primitive Solar System that gave birth to them.
Most extraterrestrial particles burn in our atmosphere, while some passes as bright stars and a small amount reaches Earth in the form of tiny meteorites.
For nearly two decades, scientists from the French National Center for Scientific Research (CNRS) measured these ground particles.
Working with the University of Paris-Saclay, the National Museum of Natural History in Paris and the French Polar Institute, scientists have suggested that 5,200 tons fall on the planet every year. This equates to roughly 14 tons of space dust per day.
The team says: “Interplanetary dust particles from comets or asteroids are particles ranging from a few tenths to hundreds of millimeters that have passed through the atmosphere and reached the surface of the Earth.”
To determine how far it reached the surface, nuclear physicist Jean Durant led six expeditions over the past 20 years to the French-Italian Antarctic Concordia Station, also known as Dome C, about 1,000 miles from the South Pole and 680 miles off the coast of Adélie Land.
With little snow and an almost complete absence of ground dust, Dome C is an ideal gathering place.
They collected enough extraterrestrial particles, ranging in size from 30 to 200 micrometers, to measure their annual fluctuations. The results found that the total annual accumulation of minute meteorites is 5,200 tons per year.
According to the French National Center for Scientific Research: “This is the main source of extraterrestrial matter on our planet, far ahead of larger objects such as meteorites, whose flow is less than ten tons annually.”
About 80% of tiny meteorites come from comets and asteroid remains, according to a study published in Earth & Planetary Science Letters.
The main elements in dust are oxygen, silicon, magnesium, iron and nickel.
Originally, the Earth’s composition was very similar to that of the sun or dust, but most of our iron and nickel went into the core, according to the physicist Durant.
He explained: “So if you take a terrestrial rock, a medium crystalline rock, it will be depleted of iron and nickel, and this is a very direct way to know whether the rocks are of extraterrestrial origin or not.”
The particles do not fall evenly over the course of the year, and are not uniformly distributed around the planet.
The scientists pointed out that the remnants of outer space do not pose any threat to humans, and can help us in “a better understanding of the role that dust particles play between the planets in providing water and carbon particles on the young Earth.”