Apr 12, 2021 15:00:00

More than 5,000 tons of minute meteorites are pouring from space to the earth every year.

Some of celestial objects flying on the earth from space,

meteorite weighing 570kg, which issued a large number of Jukeisho's by a huge explosion Some, size is there is only a fraction less than one of 1mm micro-meteorites there is also. For more than a decade, research on micrometeorites from the snow that has accumulated in Antarctica has revealed that the amount of micrometeorites that fall from space onto the earth reaches 5,200 tons per year.

The micrometeorite flux at Dome C (Antarctica), monitoring the accretion of extraterrestrial dust on Earth --ScienceDirect
https://www.sciencedirect.com/science/article/pii/S0012821X21000534

5,200 Tons of Extraterrestrial Dust Rain Down on Earth Every Single Year
https://www.sciencealert.com/5-200-tons-of-micrometeorites-are-raining-down-on-earth-s-surface-every-year

More than 5,000 tons of extraterrestrial dust fall to Earth each year
https://phys.org/news/2021-04-tons-extraterrestrial-fall-earth-year.html

A research team led by Jean Dupra, who studies micrometeoroids at the Center National de la Recherche Scientifique (CNRS) , conducted a total of six expeditions near Concordia Station in Antarctica, and conducted a total of six expeditions to the Antarctic called Dome C. Samples of micrometeoroids were collected from the ice sheet. Dome C has a small amount of snow and almost no earth and sand, so it is a perfect place to find micrometeorites that fall from space.

In the six expeditions of 2001, 2002, 2005, 2006, 2015 and 2016, the research team produced

808 space spherules (melted space rocks) with a mass of less than 350 micrograms. When……

We found 1280 micrometeorites that were not melted, for a total of 2088.

Then, when the research team calculated the amount of descent on the entire earth from the amount of samples collected, the result was that about 3600 tons of space spherules and 1600 tons of micrometeoroids, a total of 5200 tons, are pouring onto the earth every year. Was done. This is much higher than the normal meteorite, which is estimated to have an annual descent of less than 10 tons, and is the largest extraterrestrial material flying onto the earth.

The research team also estimated from the analysis of the collected samples that 80% of the cosmic dust flying on Earth was emitted by comets. This is in line with previous studies' estimates of the amount of comet-derived material flying over Earth.

On the other hand, the research team estimates that 'the total amount of cosmic dust before entering the atmosphere is about 15,000 tons per year' according to another calculation. It is not clear why only one-third of the micrometeorites are falling on the earth, but 'cosmic dust has been removed before entering the atmosphere' and 'less cosmic dust exists in outer space around the earth'. It is speculated that it is one of 'a considerable proportion of cosmic dust has slipped through detection'. The research team hopes that if one of these three theories is correct, it will be possible to clarify how the water and carbon molecules necessary for the birth of life were brought to the early Earth. I will.