Is Earth Special?
Lead Supervisor: Prof David Waltham
Location: Department of Earth Sciences, Royal Holloway University of London
Duration: 6 weeks
Suitable undergraduate degrees: Physics, astrophysics
Peculiar conditions may be required for the origin of life and/or the evolution of complex organisms. Hence, Earth attributes—such as plate-tectonics, oceans, magnetism and a large moon—may be necessary preconditions, for our own existence, that are rare in the general population of planets. The unknown magnitude of this observational bias undermines understanding of our planet—we do not know if Earth is a fairly typical, rocky planet or, instead, one of the oddest worlds in the Universe. This makes it impossible to support any claim that we have a deep understanding of the Earth.
However, recent advances in computer modelling the interacting physical, chemical and biological processes controlling the whole-Earth-system, combined with hard-data now emerging from the characterization (rather than mere discovery) of exoplanets, may now allow a more scientific and rigorous approach to tackling the question “is Earth special?” Specifically, Earth-system models allow us to better understand how Earth’s properties (composition, mass, formation history etc) affect habitability (e.g. climate history) whilst exoplanet characterization will allow us to determine how common the critical property combinations are.
This project will investigate a specific example of an Earth property that may be critical to its habitability and that may be rare in the population of planets—the fact that Earth has a large moon. In particular, it aims to automatically scan the entire Kepler catalogue of exoplanets to look for evidence of moons orbiting them. So far, no such exomoons have been found by any teams (there have been provisional announcements, but these have not been supported by later research). However, a previous UG project in RHUL’s Earth Science department has developed a promising approach that is suitable for automation and which could, therefore, allow the entire Kepler Catalogue of 4000 exoplanets to be searched for evidence of exomoons. The proposed project will write the Python code needed to automate the search.
It should be emphasised that this will not, on its own, prove the existence of any exomoons but it will identify candidates for further follow up. Demonstration that the automation works, and publication of the resulting exomoon candidates, will be publishable research.
Waltham, D., 2019. Is Earth Special? Earth-Science Reviews, 192, 445-470.