# Tons of dust: Significant particles

Calculations made on the basis of satellite observations and extrapolations, suggest that daily on our planet from space in one form or another 5 to 300 tons of matter falls. How much is it? Answer this is designed by the new Codita project (Cosmi Dust in the Terrestrial Atmosphere – "Space Dust in the Earth Atmosphere"). "While it’s just a mystery: the assessments of the mass of dust differ in two orders of magnitude," says one of the authors of the project Briton John Plein (John Plane) – so the goal of Codita is to narrow this scatter ".

In fact, only at first glance the outer space is empty. It is simply extremely rareered, but if you take, for example, all dust particles, flexing within the orbit of Jupiter, can be folded the dense body about 25 km in diameter. All this – the fragments of the substance that has survived from the era of the formation of the planets, particles of comets, fragments of colliding asteroids and so on – often falls to Earth.

Analysis of the content of this dust of the elements (usually, iridium and osmium) in the polar ice hats and seabed deposits, shows that our planet is 100-300 tons of such a substance. On the other hand, there are observations of observations conducted by observatory and satellites that give a completely different digit – 5 tons per day.

It would seem what, in general, the difference? However, there is a difference. John Plein comments: "If the flow of dust is about 200 tons per day, then it should be recognized that the speed of movement of these particles down through the earth’s atmosphere is much more than it is considered today. If closer to the reality of the figure in 5 tons, it will be necessary to revise the views on the origin and movement of dust particles in the solar system.

According to reports, dust particles are included in the upper layers of our atmosphere at very large speeds, from 38 thousand. up to 248 thousand. km / h, depending on whether they moved around the sun in the same direction as the Earth, or in the opposite. Faced with air molecules, they quickly rake, reaching the temperature of 1600 OS. Particles with dimensions of more than 2 mm start glowing and visible as "falling stars", but the overwhelming number does not reach this value and can be detected only by special tools.

Apparently, they, evaporating, bring a whole bunch of metals to the atmosphere, significantly affecting its condition capable of creating some celestial phenomena and even affect climate. "Space dust is apparently related to the formation of silver clouds," explains John Plein, – the highest in the atmosphere of the Earth. Its particles can serve as a surface on which ice crystals are based on. Such clouds appear in summer in the indoor areas, their formation is associated with climatic changes ". We add that clarity in the causes and mechanisms of the appearance of silver clouds still do not. More details we wrote about them in the article of the same name: "Silver clouds".

In addition, metal elements brought by dust affect the formation and existence in the stratosphere of ozone and the ozone layer. Therefore, the exact knowledge of the number of this dust is required to find ways to preserve the ozone layer and understanding his role in the life of the planet. Space dust saturates the ocean with iron, affecting the life of plankton. In a word, a tricky little thing at closer looks at all is not the trifle. Therefore, there was such a project like Codita.

Currently, the authors have already received a grant from the European Union in the amount of 2.5 million euros for the next five years. The international Codita team united under the leadership of the already familiar to us John Plain more than 20 scientists from the United Kingdom, USA and Germany. Work began.