The role of giant impacts in the formation of the outer solar system and exosystems

巨大撞击在外太阳系和系外系统形成中的作用

• 批准号: 2815106
• 金额: --
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2815106
• 关键词: role; giant; impacts; formation; outer

Giant impacts (collisions between planet-sized bodies) are the most violent events in planet formation. For a few hours, collisions that form greater than Earth-mass bodies release more energy than the Sun. Large fractions of the icy and/or rocky mantles of the colliding bodies are melted and vaporised, and the huge torques exerted can leave the post-impact body rapidly rotating. The mass of the largest body may either increase or decrease, depending on the amount of material ejected from the system. Impacts can fundamentally alter the trajectory of a planet's evolution, as the ratios of atmosphere, crust, mantle and core all change and systems of moons can be formed. For example, giant impacts are thought to be responsible for the high obliquity of Uranus, the high density of Mercury, and the formation of Earth's Moon. This project will explore how collisions shape the planets in our solar system and in exosystems. Using state-of-the-art giant impact simulations, the Lucy will investigate the range of dynamic and thermodynamic outcomes of collisions between water-rich bodies, and develop 'scaling laws' that relate the outcomes to the impact parameters. Although generally a common occurrence, the rates and energies of impacts vary between different planet formation models. By analysing the frequency and parameters of impacts in each scenario, Lucy will ascertain how giant impacts would sculpt planetary systems in different cases. Furthermore, by determining the observational signatures of post-impact bodies and synestias, the project will aim to provide the tools necessary to identify synestias, and other post-impact bodies, in other solar systems.

巨大的撞击（行星大小的物体之间的碰撞）是行星形成过程中最剧烈的事件。在几个小时内，形成比地球质量更大的天体的碰撞释放出比太阳更多的能量。碰撞体的大部分冰和/或岩石地幔被融化和蒸发，施加的巨大扭矩可以使碰撞后的物体快速旋转。最大物体的质量可能增加或减少，这取决于从系统中喷出的物质的数量。撞击可以从根本上改变行星的演化轨迹，因为大气、地壳、地幔和地核的比例都发生了变化，卫星系统也可以形成。例如，巨大的撞击被认为是造成天王星高倾角、水星高密度和月球形成的原因。这个项目将探索碰撞如何塑造我们太阳系和系外系统中的行星。利用最先进的巨型撞击模拟，“露西”号将研究富水天体之间碰撞的动态和热力学结果范围，并制定将结果与撞击参数联系起来的“比例定律”。虽然撞击的频率和能量在不同的行星形成模型中是不同的，但这是一种常见的现象。通过分析每种情况下撞击的频率和参数，“露西”号将确定在不同情况下，巨大的撞击会如何塑造行星系统。此外，通过确定撞击后天体和索内斯蒂亚斯的观测特征，该项目将旨在提供必要的工具，以识别其他太阳系中的索内斯蒂亚斯和其他撞击后天体。