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Kochan Hermann W. Huebner Walter F. Sears Derek W. G. 《Earth, Moon, and Planets》1998,80(1-3):369-411
Comet simulation experiments are discussed, in the context of physical models and the results in cometary physics, gathered
especially from the GIOTTO space mission to comet P'Halley. The “status of the today knowledge” about comets, the experiments
could start from, is briefly reviewed. The setup of the KOSI (German = Kometen Simulation) - experiments and the techniques
to produce cometary analogous material, on the basis of that knowledge are described in general, as for the different KOSI
experiments. The limitations of the simulation of physical processes at the surface of real comets in an earth-bound laboratory
are discussed, and the possibilities to receive common insights in cometary physics are shown. Methods and procedures are
described, and the major results reviewed. As with attempting to reproduce any natural phenomenon in the laboratory, there
are short-comings to these experiments, but there are possibly major new insights to be gained. Physical laws only have the
same consequences under same experimental or environmental conditions. A number of small-scale comet simulation experiments
have been performed, since the early 60ties in many laboratories, but the largest and most ambitious series of comet simulation
experiments to date were performed between 1987 and 1993 using the German space agency's (DLR) space hardware testing facilities
in Cologne. These experiments were triggered by the scientific community after the comet P'Halley's recurrence in 1986 and
the many data gathered by the space missions in this year. Simulation experiments have proved valuable in developing methods
for making cometary analogues, and for exploring specific properties of such materials in detail. These experiments provided
new insights into the morphology and physical behavior of aggregates formed out of silicate- /water-ice -grains likely to
exist in comets. The formation of a dust mantle on the surface, and a system of ice layers below the mantle from the different
admixed materials, have been detected after the insolation of the artificial comet. The mechanisms for heat transfer between
the comet's surface and its interior, compositional, structural, and isotopic changes that occur near the comet's surface,
were described by modeling in accordance with the experimental results. The mechanisms of the ejection of dust and ice grains
from the surface, and the importance of gas-drag in propelling grains were investigated by close-up video cameras.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Ehrenfreund Pascale Krafft Catherine Kochan Hermann Pirronello Valerio 《Earth, Moon, and Planets》1998,80(1-3):1-1
Earth, Moon, and Planets - 相似文献
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