| Project/Area Number |
04835001
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
惑星科学
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| Research Institution | (Institute of Low Temperature Science), Hokkaido University |
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Principal Investigator |
AKITA Kouchi Institute of Low Temperature Science Hokkaido University, Instructor, 低温科学研究所, 助手 (60161866)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1993: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1992: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Amorphous ice / Thermal conductivity / Comet |
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| Research Abstract |
The thermal conductivity of very slowly deposited amorphous ice derived from experimental results is shown to be a factor of 10^<-3> to 10^<-4> less than hitherto estimated. Calculations using comet nucleus thermal conductivities derived from the new results show that : (1) the temperature of all new comets is lower than the temperature at which they formed-generally reduced by 1/2, and (2) significant elevation of temperature within periodic comets is generally limited to depths of the order of centimeters of tens of centimeters. The conclusion reached is that the Comet Nucleus Sample Return mission need probe only to tens of centimeters beneath the nucleus surface to recover material which accurately reflects the interstellar cloud out of which the solar system was born.
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