Planetary Origins and Evolution at Imperial (2022-2025)

How do planetary systems develop and is life unique to our planet? This is one of the most fundamental of questions in science and has deeply profound implications for our place in the cosmos. It is thus a key scientific challenge set by the Science and Technology Facilities Council.

Our planetary science research program investigates the origins and evolution of our solar system to understand the amazing diversity of planets and small worlds orbiting the Sun and determine when and where life might exist beyond Earth. A particular focus is the process and consequences of solar system collisions, which build planets from dust and ice, transfer rocks, volatiles and organics between bodies, deliver a regular flux of cosmic dust and sculpt and modify planetary surfaces to this day.

How planetary materials changed after the dust was assembled into larger bodies is crucial in making planets that are suitable for life. Our research will examine whether primitive planetesimals, the early forerunners of planets, melted and mixed internally by examining the evidence for early magnetic fields within meteorites. Our research will evaluate whether ancient magnetic traces already found in meteorite minerals are reliable indicators of the dynamos of metallic cores, as well as magnetic fields within the gas and dust cloud from which our solar system formed. This depends critically on understanding how effective impacts are at resetting or overprinting the magnetic record in meteorites.

Volatile constituents are vital to life but easily lost by heating and they differ greatly in abundance between planets in our solar system. Our research focuses on the volatile budgets of the terrestrial planets, to identify the source of the volatiles and determine when they were added. For this, the research examines the isotopes of zinc, germanium and tellurium and is made possible by technology and method advances that will be pioneered in the study. As such, the work will help us understand how and when Earth acquired the ingredients essential to the formation life.

Following the water, our research will also develop new techniques to use space dust that falls continuously on the surface of the planets as a "litmus paper" to identify the past presence of water on the surface and in the atmosphere. Since these particles will be abundant in martian soil of different ages, and water is an important prerequisite for life on the planet, our research will reveal the ancient history of Mars and identify possible periods of habitability.

Our research will also examine some of the largest and most dramatic impact events in early solar system, such as the glancing collision that formed the enormous 2500-km wide South Pole-Aitken basin on the Moon. When humans return to the Moon later this decade they will land on the rim of this huge crater. Understanding how the impact reshaped the Moon is critical to interpreting the rocks the astronauts will walk on and using what they find to determine what the Moon is made of and how it formed. Using state-of-the-art computer simulations, we will replicate this impact to determine how otherwise inaccessible material from deep inside the Moon was redistributed and where it landed. We will also model similar impacts on Earth to understand how material can be transported from one planet to another, and whether this might include living things.

Finally, our research will enhance our ability to detect life in space. We will develop new techniques to search for the chemical signature of life and distinguish them from inorganic chemistry that forms without living things present. This project will combine AI machine learning with laboratory experiments and numerical simulation of molecules to search the large amounts of data generated by planetary missions for the spark of life. The methods developed by the study will be particularly useful for the forthcoming NASA Europa Clipper mission to the moons of Jupiter.