On the roofs of houses found cosmic dust
Scientists discovered particles of cosmic dust on the roofs of houses in Paris and Oslo.
This was reported in an article published in the journal Geology.
Yet in the 40-ies of the last century, researchers have known that the Earth’s atmosphere are constantly fine particles of cosmic dust. The most popular place to find them is usually considered to be Antarctica. This is because the air is less polluted than in other parts of the world, and the dark dust substance noticeable on pure white snow.
However, scientists are still trying to find particles that came from outer space, and in the cities that make particularly difficult, since there accumulate a lot of dust of terrestrial origin (the source are the transport and industry). However, researchers from the UK, Norway and Belgium reported that they managed to find space dust directly into the roofs of houses.
The Roof Of Oslo
The authors collected 300 kilograms of dust, which has accumulated in the gutters of the houses being in Paris and Oslo. Using magnets, they selected particles containing magnetic minerals, and then washed with water and separated by size. Geologists then examined the samples under a microscope and selected only those particles which had the characteristic of cosmic dust features: spherical or subspherical shape, black or grey color and luster and also special structure of the surface.
In the end, the researchers were able to “catch” 500 silica particles of cosmic dust.
They all had subspeices form and reached 0.3 mm in diameter. It came as a surprise to geologists, as they are usually found much smaller samples, with a size of about 0.01 millimeter. In addition, as reported in New Scientist, urban particles differed from the Antarctic that contain smaller crystals branching structures (dendrites).
Scientists believe that all particles fell to the Ground in the last six years, which means that they can be considered the most “fresh” micrometeorites today.
Their unusually large size of the geologists explained that the orbits of the planets, including Earth and Mars, evolyutsioniruet, that is slowly changing its parameters. This results in gravitational perturbations that can affect the trajectory of dust particles and the rate at which they enter the atmosphere of our planet, which in turn affects their size.
The Rooftops Of Paris
Recently, scientists from NASA analyzed the particles of cosmic silicate dust, which they were able to find in the fallen to our planet in meteorites. It turned out that about one. 5 thousand particles was born of another star, which had existed before the formation of the Solar system. Research dust also conducted by the station “Cassini”, which recently embarked on a series of “dives” near the F-ring of Saturn. The spacecraft collected particles had approximately the same chemical composition and probably appeared due to unknown repetitive process that occurs in the interstellar medium.