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Interstellar dust

What an interstellar dust?

 Automatic translation  Automatic translation Updated June 01, 2013

The dust we see in the Universe or in our solar system is not the same as what we know on Earth or in our homes. Dust in the Universe are found everywhere and especially in the nebulae, with the dense gas, encourage the birth of stars.
The dust that walks through the Solar System comes mainly asteroids and comets and the beginnings of the training system, while the dust of our homes is primarily produced by erosion of objects and the remains of ashes. The interplanetary dust particles captured is composed of glass, carbon and an agglomeration of micro grains of silica minerals. It measures 10 microns wide, or one tenth the diameter of human hair. Silicon readily combines with oxygen to form silicon dioxide (SiO2). Moreover, silicon is the main constituent of the earth's crust (25.7% by mass) after oxygen (46.4%).


The research of this type of particle is due to dust collectors embedded in the satellite space specially designed for this purpose. In the structure airgel dust collectors, scientists extract the particles that need to be studied, taking approximately 1.5 million photographs through a powerful microscope. Each of the photographs covering only a very small section of the racquet collection.

Image: Image of an interplanetary dust of 10 microns, captured by a U2 aircraft at high altitude (2001).
Credit NASA


In search of dust


The mission of the STARDUST spacecraft (Stardust) launched by NASA February 7, 1999, was to collect interstellar dust.
It is passed through the tail of Comet Wild 2 in January 2004 and returned to Earth January 15, 2006 after collecting a large amount of cometary and interstellar dust. This is the first probe to be brought back comet particles, it has traveled 4.5 billion kilometers in the solar system.
The new mission of the STARDUST spacecraft, since July 2007, is the flyby of comet Tempel 1 February 14, 2011. Tempel1 had been deliberately struck by the impactor of the Deep Impact spacecraft to obtain more information on cometary dust and interstellar particles. Stardust is 1.7 m long, 66 cm wide and deep, and weighs 385 kg (254 kg probe, 46 kg for the module back and 85 kg of fuel).
The analysis of photographs taken by STARDUST is huge.


That's why NASA launched the Stardust @ home calling for help the Internet community. Stardust @ home volunteers encourages users to search for interstellar dust impacts through a virtual microscope.

Image: The particle collector (Airgel sample collector) of the Stardust SRC (Sample Return Capsule), the return capsule. Different dust is captured in the airgel resembling foam. The collector is approximately 1 m² surface, which is set airgel. One side is used to collect interstellar particles, and the other to that of cometary particles. When a particle at high speed in contact with airgel it enters into a widening cone of more than 200 times its own length.

 collecteur de particules

Dust builds stars and planets


Nebulae, the Latin word 'nebula' (cloud), composed of clouds of gas and dust among the stars, are both active nurseries and cemeteries of stars.
The splendors of dust clouds are illuminated by the stars they contain or the stars behind them.
These are the most beautiful astronomical images that can be achieved currently. The nebulae are we admire in the telescope field of wonderful cities of stars, interstellar dust and gas flooding the sky. More Telescope is the most powerful images are wonderful.
The long exposures reveal the entire palette of colors in particular the stunning pink hydrogen. William Herschel discovered the dark nebulae, clouds of gas and dust without a star, too dense to let the light of stars behind.


Image: In one image all the splendors of the center of the Lagoon Nebula, or NGC 6523 or M8.
The dust spread over almost the entire image, leaving just see the bright star Herschel 36, which illuminates the area. Vast walls of dust mask and redden other hot young stars barely visible in transparency, in this photograph.

 poussières de nébuleuse

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