Planetary Science at Bristol

我们将及时返回载人阿波罗12-16号登月任务的遗产：一个广泛的地震数据集。这个记录了超过12500次“月震”的数据集已被广泛用于对月球的深层结构进行成像，但这些研究只提供了静态图像。地震各向异性使我们能够探测地下动力学，但它的测量是具有挑战性的复杂的月球数据。最近的进步，在分析技术开发的嘈杂的地面数据，现在使这些测量成为可能。这种测量可以用来探测月球地幔中的对流等过程，甚至可以判断月球内部深处是否仍然存在月球火热诞生时的炽热熔融痕迹。与地球的月球不同，土星的巨大卫星泰坦有一个厚厚的大气层，其中含有腈和碳氢化合物的奇异混合物。土卫六提供了一个天然的实验室来测试我们对大气化学和物理学的理解。它与地球也有许多相似之处，包括极地涡旋和独特的极地化学成分，这些都可以让我们深入了解我们自己的星球。来自卡西尼号航天器和詹姆斯韦伯太空望远镜的大量数据将用于研究泰坦的大气层。特别是，我们将研究大气波的作用，极端寒冷和极地反馈，以及轨道对泰坦季节的影响。除了大型卫星，我们还将研究小型小行星体。特别是，我们将试图解释最近的missios获得的高清晰度图像上发现的表面特征。我们试图解释“低地”地形。这项研究的目标是了解小行星的形状、旋转周期和整体大小的变化如何影响低地的形成，以帮助选择未来的采样返回任务目标。 当行星物体碰撞时，蒸发就会发生，这是它们在原太阳周围的气尘盘中生长的不可避免的一部分。然而，以前人们认为，挥发性较低的主要组成部分，硅和镁（地球质量的1/3）不受影响。我们小组的新测量表明，地球原始质量的约50%被蒸发，挑战了这一范式。然而，没有实验数据证实蒸汽损失在形成行星组成方面的重要性。我们提出了创新的实验和分析，以确定必要的液体-蒸汽化学相互作用，并解决这一知识差距，使我们能够更好地模拟行星的形成过程。水对于理解类地行星的形成和可居住性至关重要。在太阳系诞生之初，小行星体是由尘埃、矿物颗粒和冰的堆积形成的。水和其他挥发性元素的加入可能发生在太阳系内的小行星带或土星和木星的轨道附近。区分这些情景对于行星增长模型至关重要。一些陨石在很长一段时间内含有少量的水被困在矿物质中。在这个项目中，我们将分析这些水的同位素组成，以确定它在太阳系中的位置。许多小行星和陨石的主要成分是毫米大小的淬火熔融液滴或球粒。这些天体形成于太阳系历史的最初几百万年，尽管确切的时间是一个相当有争议的问题。这是一个具有挑战性的问题，因为我们需要在超过45亿年的物体中区分小于100万年的时间周期。然而，在一个快速演化的早期太阳系中，能够可靠地绘制陨石球粒在适当时间段的形成是一个重要的问题。我们将应用一种新的约会方法，我们已经开发了作为以前的STFC资金的一部分，希望调和目前对比的解释。

We will make a timely return to a legacy of the manned Apollo 12-16 missions to the moon: an extensive seismic dataset. This dataset recorded of over 12500 'moonquakes' has been used extensively to image the deep structure of the moon, but these studies only provide a static picture. Seismic anisotropy enables us to probe subsurface dynamics, but its measurement is challenging for the complex lunar data. Recent advances in analysis techniques developed for noisy terrestrial data now make these measurements possible. Such measurements can be used to probe processes such as convection in the lunar mantle, or even tell whether there are still hot, molten traces of the moon's fiery birth deep in the interior.Unlike the Earth's moon, Saturn's giant moon Titan, has a thick atmosphere with an exotic mix of nitriles and hydrocarbons. Titan provides a natural laboratory to test our understanding of atmospheric chemistry and physics. There are also many similarities with Earth including polar vortices and distinct polar chemical compositions, that can provide insight into our own planet. A wealth of data from the Cassini spacecraft and the James Webb Space Telescope, will be used to study Titan's atmosphere. In particular we will examine the role of atmospheric waves, extreme cold and polar feedbacks, and orbital influences on Titan's seasons. As well as the large moons, we will also study small, asteroid bodies. In particular, we will attempt to explain surface features discovered on high definition images obtained by recent missios. We seek to explain 'lowland' topography. The goal of this research is to understand how changes in shape, spin-period, and overall size of the asteroid influence the formation of lowlands, to assist in the selection of future targets for sample return missions. Vaporisation occurs when planetary objects collide, as an inevitable part of their growth in the gas-dust disk around the proto-Sun. Yet it was previously assumed that the less volatile major building blocks, silicon and magnesium (1/3 Earth's mass) were unaffected. New measurements from our group suggest ~50% of Earth's original mass was vaporised, challenging this paradigm. However, there are no experimental data to substantiate the importance of vapour loss in shaping planetary compositions. We propose innovative experiments and analysis to determine the necessary liquid-vapour chemical interactions and address this knowledge gap, allowing us to better model planetary forming processes.Water is vital to understanding the formation and habitability of terrestrial planets. At the birth of the Solar System small planetary bodies formed through the accretion of dust, mineral grains and sometimes ice. The addition of water and other volatile elements to these small planetary bodies may have taken place in the inner Solar System asteroid belt or near Saturn and Jupiter's orbit. Distinguishing between these scenarios is critical for models of planetary growth. Some meteorites contain small amounts of water trapped in minerals over this long time period. In this project we will analyse the isotopic composition of this water to fingerprint to where in the Solar System it was added. A prime constituent of many asteroids and meteorites are millimetre sized, quenched melt droplets or chondrules. These objects formed in the first few million years of solar system history, although exactly when is a matter of considerable debate. It is a challenging problem as we need to distinguish time periods of less than 1million years in objects more than 4.5 billion years old. Yet it is important problem to be able to reliably map the formation of chondrules on the appropriate time period in a rapidly evolving early solar system. We will apply a novel dating approach we have developed as part of previous STFC funding to hopefully reconcile currently contrasting interpretations.