Rheology of non-water ice: Implications for thermal and impact histories of large icy satellites

2015 Fiscal Year Final Research Report

• Project/Area Number: 25870419
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Solid earth and planetary physics; Petrology/Mineralogy/Economic geology
• Research Institution: Kobe University
• Principal Investigator: Yasui Minami 神戸大学, 理学研究科, 助教 (30583843)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 巨大氷衛星 / 熱進化モデル / non-water ice / レオロジー / 周期振動実験 / エネルギー減衰率 / 衝突史 / 衝突破壊強度

Outline of Final Research Achievements

To study the thermal and impact histories of giant icy satellites, a large vacuum chamber combined with a pulse tube refrigerator was developed, and the samples of water ice and ethanol ice were made in this chamber. Before making ice samples, dry nitrogen gas was circulated into the chamber to remove the frost which affects the conditions of sample surface and the degree of vacuum.
Forced oscillation experiments were carried out to study the attenuation Q by using three materials (gum, sponge, and acrylic) simulating ice. The attenuation Q decreased exponentially with the decrease of the frequency.
Finally, multiple impact experiments of water ice target were carried out to determine the impact strength. This parameter is also important to study the impact histories of icy satellites. The impact times were set from 1 to 10 times. As a result, the impact strength could be expressed as the total impact energy given to the same target, irrespective of impact time.

Free Research Field

実験惑星学