Meteorite bombardment of the inner solar system - a lunar regolith perspective

This project will provide the first comprehensive inventory of the timing of meteorite impacts on the Moon using the fine-grained lunar regolith (or soil).

This will be achieved by applying a novel ion-microprobe U-Pb method to date silicate glass beads quenched from aerosols ejected from impact melt sheets and distributed over several hundreds of kilometres, as well as U-rich minerals crystallised from the in situ melts.

Dating these impacts, which are recorded in the regolith over the entire 4.5 Ga history of the Moon, will constrain the impact history of the entire inner Solar System.An original set of regolith samples will be selected from each of the Apollo, Luna and Chang’e-5 landing sites and acquired on loan from their hosting agencies.

Once received, separation of potentially datable components and their geochemical characterisation will begin.

Selected material will be dated as soon as it has been characterised and results will be published as each site is completed.

Finally, a global synthesis will be made and published.By advancing our knowledge of the impact history of the Moon, results from this project will allow better calibration of the crater counting method used to remotely date planetary surfaces and contribute to a broader understanding of the impact flux in the early Solar System, its ability to change the course of planetary evolution by influencing tectonics, as well as the delivery of exotic material, volatiles and even the building blocks of life.