Venue: The Linnean Society of London, Burlington House, Piccadilly, London, W1J 0BF, UK
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Molten Exoplanets as a Window into the Earliest Earth
Dr Tim Lichtenberg (Winton Award Geophysics delayed from March 2023)
Due to the absence of a reliable rock record from the Hadean eon, our understanding of the environment that gave rise to life on our own planet is clouded. Current and upcoming exoplanet surveys, however, significantly widen our view of the distribution and variability of rocky planets and their chemical inventories, giving opportunity to test scenarios of early planetary evolution and atmospheric formation. I will describe how rocky exoplanets in a partially or fully molten state open a novel window into on the earliest, high-temperature evolutionary regime of rocky worlds. Increasing reconnaissance of high-temperature super-Earths will enable us to infer the early climatic and geodynamic evolution of temperate rocky worlds, providing crucial information on the environmental context of the origins of life on Earth and are the next key step toward the characterisation of prebiotic and potentially habitable exoplanets.
Dr Tim Lichtenberg: PhD 2018, ETH Zurich, Department of Earth Sciences, 2018-2022 SNSF & Simons Postdoctoral Fellow, University of Oxford, Atmospheric Physics Since autumn 2022, Assistant Professor, Kapteyn Astronomical Institute, University of Groningen
Understanding the Earth’s radiation belts: our local, superscale, relativistic particle accelerator
Dr Oliver Allanson (Fowler Award Geophysics)
Understanding the dynamics of energetic electron populations in the Earths outer radiation belt presents opportunities to grapple with the fundamental physics of charged particle acceleration in our own 'back-yard', replete with in-situ and ground based instruments to validate and constrain new theories. Further, the many space weather hazards associated with this relativistic particle population in near-Earth space provide an imperative to understand, reduce, and mitigate risk where possible. We present a survey of radiation belt theory and modelling. On the one hand our understanding of the radiation belt dynamics has evolved a great deal in the 60+ years since their discovery. However, there are many aspects yet to be fully understood, with a flurry of theoretical and numerical investigations inspired in by discoveries made by satellite observations. We focus on some current cutting-edge developments, and outline exciting future directions for understanding charged particle dynamics due to interactions with electromagnetic waves in our neighbourhood super-scale particle accelerator.
Dr Oliver Allanson is an Assistant Professor in Space Environment in the Space Environment and Radio Engineering (SERENE) group, in the School of Engineering. He is also an Honorary Senior Lecturer in Mathematics at the University of Exeter. He leads a UKRI NERC Independent Research Fellowship to better understand (and improve our modelling of) space science and space weather (2021-26): The Importance of Nonlinear Physics in Radiation Belt Modelling. His current work considers the fundamental theory, modelling and observations of high-energy charged particle dynamics in the plasma of Earth's radiation belts, within our magnetosphere. This relies upon pushing the boundaries of our understanding of the kinetic plasma physics of resonant interactions between charged particles and electromagnetic waves.
Weighing exoplanets through a telescope network
Dr Annelies Mortier
The radial velocity (RV) technique, using high-resolution spectra, is currently the only viable technique to measure masses of small exoplanets. Due to inherent limitations of the transit technique, longer period exoplanets such as those resembling planets in the Solar System, are also better detected via RVs. An inherent barrier to finding many small long-period exoplanets is observing time. Due to the combination of signal aliasing, stellar variability, and the long-period nature of these planet signals, it is crucial to have densely sampled data over a long period of time. This talk will describe the current state of the field, the need for a stabilised spectroscopy network, and the wide variety of science such a network can unlock.
Annelies Mortier is an assistant professor at the University of Birmingham. After her undergraduate studies at the Universities of Ghent (Be) and Leiden (NL), she obtained her PhD from the University of Porto (PT). Before moving to Birmingham in 2022, she has done a postdoc at the University of St Andrews and a senior Kavli Fellowship at the University of Cambridge. She is an observational astronomer playing around with stars and their exoplanets.