© Photo: ESA / Rosetta / MPS for OSIRIS Team MPS / UPD / LAM / IAA / SSO / INTA / UPM / DASP / IDA
© Photo: ESA / Rosetta / Navcam
MOSCOW, 6 February -. RIA Novosti “Dumbbell” comet 67P / Churyumov-Gerasimenko, in spite of its extremely low weight, does not contain a large void, which means that the primary matter of the solar system was unusually loose and porous, reports ESA.
According to the current estimates of scientists, the comet’s mass is about 10 billion tons, which is 20 million times heavier than the largest man-made object in space, the International space Station. This is a fairly small figure for a celestial body about the size of the comet Churyumov-Gerasimenko. The secret lies in the ease of an extremely high degree of porosity of the comet -. 70-80% of its total volume occupied by the voids, and its density is about the same as in traffic jams, wood or airgel
Therefore, says Martin Petzold ( Martin Patzold) from the University of Cologne (Germany), astronomers have a question – are distributed whether these voids by comet bowels regular intervals, or low density of this celestial body is due to the fact that within it there are large “cave” and a network of large voids
Scientists have been able to answer this question comprehensively studying the gravitational field of the Churyumov-Gerasimenko comet using ingenious methods of observation, use the probe “Rosetta”, studying the comet from August 2014, and a number of radiotarelok in the world.
Petzold and his colleagues used the fact that the comet’s attraction effect on the way the “Rosetta” exchanged information with the Earth, affecting the frequency of the radio signal, which traveled from the probe to the ground stations.
© Photo:. N. Thomas et al, SCIENCE, VOL347, ISSUE 6220 (2015)
When the probe came closer to the comet, fluctuations in the power of its attraction which arose as a result of irregularities in the density of its interior, a special effect on the signal, making it a wave a little shorter when driving over a particularly dense areas, and slightly longer – while passing over voids
These fluctuations in the radio frequency. help article authors make a reasonably accurate gravity map of the comet Churyumov-Gerasimenko, find all large voids and re-measure its mass and calculate the average density. It turned out to be almost the same as the previous measurements have shown – the mass of the comet was almost the same as 10 trillion tons, and density – about 530 kilograms per cubic meter.
© ESA / ATG medialab
in turn, the bowels of the comet, judging by its gravitational map, do not contain any one large “cave”, whose size exceeds a few hundred meters. This means that matter 67P extremely friable in nature – it is about 72-74% consists of pores and other microscopic voids, occupying the space between the dust and ice grains
Most of the comet dust subsoil takes -. It 67P in the rocks about four times larger than the ice crystal, remaining inside this “shaggy beasts” from the time of birth of the Sun, Earth and other planets. Accordingly, the discovery of the high friability and porosity comet bowels says that the primary matter of the solar system with similar properties.
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