Evolution of solar system materials and bodies under hypervelocity impact

这项工作使用超高速撞击（以1公里/秒以上的速度粗略撞击）来探测与行星科学有关的一系列现象，我们将研究超高速撞击中涉及的冲击是否会撞击不同冰和化学物质的混合物的目标，可以制造氨基酸和其他复杂的有机分子，这些分子是生命的成分。如果可以的话，这可能是一种在太空中冰冷的天体（如彗星核或外行星的冰冷卫星）上产生大量这些关键分子的方法。我们还将研究在超高速撞击过程中，掺有此类化合物的冰是否能成功地将化合物输送到目标。例如，这可能是这些化合物到达早期地球的途径。我们将通过实验室实验和计算机模拟来探索这一点。关于撞击坑的形成过程，我们将从热岩石中的撞击坑开始，这是金星和水星表面的典型情况，我们有来自太空任务的数据，显示撞击坑的存在。岩石的性质随温度而变化是众所周知的，但在撞击坑形成中没有得到广泛的考虑。我们探索这一点，在我们自己的枪加热目标，然后尝试使用计算机程序模拟的结果，测试代码中的模型的有效性。我们还将看到冰中混入沙子的环形山。这是太阳系中某些类型的冰体的现实情况，它们不是纯水冰，但可能含有不同数量的硅酸盐。同样，我们将支持实验工作（从我们的枪）与计算机为基础的建模。除此之外，我们还将直接研究彗星和星际尘埃，为美国宇航局的星尘使命进行数据分析，该使命于2006年将这些尘埃的样本从太空送回地球。我们有成功参与研究这些样本的历史，并将继续这样做。我们不仅在实验室中研究它们，而且还使用我们的枪创建模拟样本，以了解当NASA Stardust航天器在超高速撞击中捕获时，真实的样本可能经历的任何修改。与我们所有的工作一样，我们将用计算机建模支持撞击实验，以更全面地了解正在发生的事情。最后，我们还将通过研究小粒子对目标的撞击，研究超高速撞击的一些基本物理学。当这些射弹的尺寸小于百万分之一米时，所产生的撞击坑的大小是对我们正确模拟高应变率撞击过程的能力的特别敏感的测试。我们将使用自己的枪对各种材料进行射击，并与建模预测进行比较。在我们的所有工作中，实验工作和计算机建模的结合将为研究这些撞击过程提供强有力的工具。所获得的结果和见解将极大地帮助我们了解太阳系中具有根本重要性的各种现象。

The work uses hypervelocity impacts (crudely impacts at speeds above 1 km/s) to probe a series of phenomena relevant to planetary science, We will look at the question of whether the shocks involved in hypervelocity impacts onto targets of mixtures of diferent ices and chemicals, can make amino acids and other complex organic molecules which are the ingredients of life. If they can, this may be a means for producing large amounts of these key molecules in space on icy bodies (such as comet nuclei or icy satellties of the outer planets). We will also investigate if ices which are doped with such compounds can successfuly deliver the compounds to targets during hypervelocity impacts. This could be a route for these compounds to arrive on an early Earth for example. We will explore this via both laboratory experiments and computer simulations. Regarding cratering process, we will start with impact cratering in hot rocks, typical of the surfaces of Venus and Mercury, where we have data from space missions, showing the presence of impact craters. That the properties of rocks change with temperature is well know, but not widely considered in impact cratering. We explore this using heated targets in our own gun and then trying to model the results using computer programmes, testing the validity of the models in the codes. We will also look at cratering in ices which have sand mixed into them. This is realistic of some types of icy body in the Solar System which are not pure water ice, but can have different amounts of silicates mixed into them. Again we will back up the experimental work (from our gun) with computer based modelling. As well as this, we will directly study cometary and interstellar dust by working on data analysis for the NASA Stardust mission, which in 2006 returned samples of these dusts from space to the Earth. We have a history of succesful involvement in studying these samples and will continue to do so. We not only study them in our laboratory, but also create analogue samples using our gun to understand any modification the real samples may have undergone when captured in space by the NASA Stardust spacecraft in hypervelocity impacts. As with all our proposed work, we will back the impact experiments with computer modelling, to more fully understand what is occurring. Finally we will also study some of the underlying physics in hypervelocity impacts, by studying impacts of small particles onto targets. When these projectiles are smaller than 10 millionths of a metre in size, the size of the resulting impact craters are a particularly sensitive test of our ability to correctly model high strain rate impact processes. We will carry out shots of various types of materials using our own gun and compare to what modelling predicts. In all our work, the combination of experimental work and computer modelling will provide a powerful tool for studying these impact processes. The results and insights gained will greatly aid our understanding of a wide range of phenomena of fundamental importance in the Solar System.