Modelling the destructive formation of moons and rings
Lead Research Organisation:
Imperial College London
Department Name: Earth Science and Engineering
Abstract
We do not know where Mars's moons came from, nor how Saturn's rings and icy moons formed. Their origins are among the longest-running unsolved problems in planetary science, and are a primary goal of upcoming space missions. Ancient Mars and Saturn's ocean-rich moons are also among the most promising places where life could survive beyond Earth. This makes studying their formation an exciting opportunity to learn both about their specific histories and about key processes that underpin planetary evolution in general.
In spite of the dramatically different planetary environments, the leading explanations for both topics involve violent collisions. Many planets and their moons and rings are thought to form via destructive impacts and tidal-disruption events, yet these fundamental processes remain poorly understood. Furthermore, studying these cataclysmic events relies heavily on numerical simulations to predict the outcome of different scenarios, as necessary comparisons for present-day observations.
However, previous studies have suffered from major shortcomings in the resolution and other aspects of their simulations. I propose a set of connected projects to both present new scenarios for the formation of these two systems, and test the competing ideas in unprecedented completeness and detail. I will use the codes I have developed to model these events with over a hundred times higher resolution, including key improvements to how planetary materials are simulated. I will combine these with machine-learning approaches to predict the outcome of subsequent collisions far more efficiently, alongside novel techniques to simulate the further evolution of the debris after the initial disruption. This is often neglected but crucial for connecting models to real-world predictions.
Mars's moons are currently thought either to be captured asteroids or to have coalesced from a post-impact disk. However, a third option has been overlooked: the partial capture of a disrupted asteroid that is torn apart by passing too close to Mars and then evolves into a disk. Furthermore, previous impact models were too low-resolution to constrain the composition of the moons. I will study and present this new alternative, and produce the first reliably resolved predictions for an impact scenario.
For Saturn's rings and icy satellites, I will examine how an impact between precursor moons could distribute massive debris throughout the system. My recently published work demonstrated the proof of concept, and I now propose to simulate for the first time the post-impact evolution of the system. I will also test a competing idea that an outer moon was destabilised and tidally ripped apart into ring-forming material. This was recently postulated, but with no direct simulations of the disruption nor the following evolution.
These projects promise a step-change in our understanding of how systems like Mars's and Saturn's could have evolved. They are particularly timely given the imminent MMX mission, for which my predictions will provide crucial comparisons for measurements, and to capitalise on the new possibilities that my recent works have opened up.
Beyond these direct benefits, through these projects I will develop novel simulation and AI-supported tools that will open up a diverse range of other valuable, previously inaccessible topics for future study, such as: the evolution of Uranus's moon and ring system in the aftermath of the giant impact that sent the planet spinning on its side; or the ejection and global distribution of debris from extinction-level impacts onto Earth.
In spite of the dramatically different planetary environments, the leading explanations for both topics involve violent collisions. Many planets and their moons and rings are thought to form via destructive impacts and tidal-disruption events, yet these fundamental processes remain poorly understood. Furthermore, studying these cataclysmic events relies heavily on numerical simulations to predict the outcome of different scenarios, as necessary comparisons for present-day observations.
However, previous studies have suffered from major shortcomings in the resolution and other aspects of their simulations. I propose a set of connected projects to both present new scenarios for the formation of these two systems, and test the competing ideas in unprecedented completeness and detail. I will use the codes I have developed to model these events with over a hundred times higher resolution, including key improvements to how planetary materials are simulated. I will combine these with machine-learning approaches to predict the outcome of subsequent collisions far more efficiently, alongside novel techniques to simulate the further evolution of the debris after the initial disruption. This is often neglected but crucial for connecting models to real-world predictions.
Mars's moons are currently thought either to be captured asteroids or to have coalesced from a post-impact disk. However, a third option has been overlooked: the partial capture of a disrupted asteroid that is torn apart by passing too close to Mars and then evolves into a disk. Furthermore, previous impact models were too low-resolution to constrain the composition of the moons. I will study and present this new alternative, and produce the first reliably resolved predictions for an impact scenario.
For Saturn's rings and icy satellites, I will examine how an impact between precursor moons could distribute massive debris throughout the system. My recently published work demonstrated the proof of concept, and I now propose to simulate for the first time the post-impact evolution of the system. I will also test a competing idea that an outer moon was destabilised and tidally ripped apart into ring-forming material. This was recently postulated, but with no direct simulations of the disruption nor the following evolution.
These projects promise a step-change in our understanding of how systems like Mars's and Saturn's could have evolved. They are particularly timely given the imminent MMX mission, for which my predictions will provide crucial comparisons for measurements, and to capitalise on the new possibilities that my recent works have opened up.
Beyond these direct benefits, through these projects I will develop novel simulation and AI-supported tools that will open up a diverse range of other valuable, previously inaccessible topics for future study, such as: the evolution of Uranus's moon and ring system in the aftermath of the giant impact that sent the planet spinning on its side; or the ejection and global distribution of debris from extinction-level impacts onto Earth.
