Jupiter’s moon Europa hosts a subsurface ocean under an ice shell of uncertain thickness. Europa has two multiring basins that exhibit several concentric rings. The formation of these multiring basins is thought to be sensitive to the thickness and thermal structure of the ice shell. Here, we simulate multiring basin forming impacts on Europa finding that a total ice shell greater than 20 kilometers thick is required to reproduce observed ring structures. Thin ice shells (<15 kilometers thick) result in compressional tectonics inconsistent with observed ring structures. Our simulations are also sensitive to the thermal structure of the ice shell and indicate that Europa’s at least 20-kilometer ice shell is composed of a 6- to 8-kilometer-thick conductive lid overlying warm convecting ice. The constraints on Europa’s ice shell structure resulting from this work are directly relevant to our understanding of the potential habitability of Europa.

中文翻译：

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多环盆地的形成限制了木卫二的冰壳厚度

木星的卫星欧罗巴在厚度不确定的冰壳下有一个地下海洋。木卫二有两个多环盆地，呈现出多个同心环。这些多环盆地的形成被认为对冰壳的厚度和热结构敏感。在这里，我们模拟了多环盆地形成对木卫二的影响，发现需要超过 20 公里厚的总冰壳才能重现观察到的环结构。薄冰壳（<15公里厚）导致压缩构造与观察到的环结构不一致。我们的模拟对冰壳的热结构也很敏感，并表明木卫二至少 20 公里长的冰壳由覆盖在温暖对流冰上的 6 至 8 公里厚的导电盖组成。这项工作对木卫二冰壳结构的限制与我们对木卫二潜在宜居性的理解直接相关。