Author: Spotlight

ISSI’s Game Changers online seminar series was launched during the first Covid-19-related lockdown in summer 2020 to help keep the community together. Up until this 100^th webinar, the series has covered a wide range of topics, from climate change on Earth to life in the universe and the Big Bang. Following an ISSI workshop on “The Geoscience of Exoplanets: Going Beyond Habitability” earlier this April, the speaker will discuss how the geosciences and the physics of the solid planet in particular, can support the search for life on exoplanets. The non-linear theory of plate-tectonics will be used to discuss the bi-stability of tectonics, climate, and the bio-productivity of Earth-like worlds. A central element to the discussion will be the role of water cycling between interior and surface reservoirs. Positive and negative feedback mechanisms will be explored along with the non-linear dependence of key rock properties on water concentration and temperature. It will be argued that the Earth, with its balanced distribution of land and ocean surface areas and its life-friendly conditions, might be rather rare. Other Earth-like worlds would more likely be “dune planets” covered mostly by land and whose biomass is water-supply limited. A less likely planet, but still more likely than Earth, would be mostly covered by ocean water and life would be nutrition-supply limited. Light curves of candidate exoplanets such as those tested for Earth with NASA’s EPOXI mission might help to statistically test the model. The title of this talk could then be reversed: How the study of exoplanets can contribute to solving conundrums for geoscientists.

Tilman Spohn is a researcher at the DLR Institute of Planetary Research in Berlin where he was Director from 2004 to 2017. From 2019 to 2022, he was the Executive Director of the International Space Science Institute (ISSI). He was Principal Investigator of the Heat Flow and Physical Properties Package HP³ on NASA’s InSight Mars mission and the MUPUS thermal probe on ESA’s Rosetta mission. From 2004–2017, he helped develop the BELA Laser Altimeter as Co-PI on the BepiColombo mission, which is now on its way to Mercury. In his theoretical studies, he modeled the thermal and tectonic evolution of Earth, the terrestrial planets and of small bodies of the Solar System. He is a Fellow of the American Geophysical Union and a member of the Academia Europaea and of the Academy of Astronautics. 

Webinar was recorded on April 25, 2024

The James Webb Space Telescope is revolutionising most areas of astrophysics. One of the most exciting and puzzling findings has been the discovery of a large population of massive black holes within the first billion years after the Big Bang. Their properties, and in particular their large masses, are difficult to reconcile with the standard black hole formation scenarios, and have required the development of new models, which are being tested against the additional constraints that are being provided by JWST.
JWST has also revealed that the interplay between these early black holes with their host galaxies was probably quite different than what observed at later cosmic epochs, with important implications for the early formation of galaxies and their stellar populations. JWST is also finding an intriguing, large population of dual black holes, which might be in the process of merging, indicating that this might be an additional route for their early growth and also an early source of gravitational waves. The webinar gives an overview of these various findings, highlighting the impressive progress made so far and also the exciting new questions that have been opened, as well as the prospects of tackling them in the coming years.

Roberto Maiolino is Professor of Experimental Astrophysics at the University of Cambridge, Honorary Professor at University College London and Fellow of the Royal Society. From 2016 to 2021 he was Director of the Kavli Institute for Cosmology, Cambridge.​He investigates the formation, evolution and transformation of galaxies and black holes across the cosmic epochs, primarily by using data collected through some of the largest telescopes. He has been playing a leading role in various large international projects, such as the James Webb Space Telescope, the next generation spectrograph for the Very Large Telescope (MOONS), and the high resolution spectrograph for the Extremely Large Telescope (ANDES).

Webinar recorded on March 21, 2024

Digital twin technologies – already established in engineering – are becoming increasingly interesting for applications in Earth sciences. Digital twins offer effective tools for dealing with the dramatic impacts of climate change and extremes on our society. They allow exploring the vast amounts of data produced by numerical models and Earth observations to identify causes and effects of environmental change on water, food, energy and health management, and for finding pathways for a more sustainable future. The enormous computing and data handling challenges for Earth-system twins can only be overcome by substantial investments in super-computing and machine learning. These are addressed by the European Commission flagship activity Destination Earth (DestinE). DestinE was launched in 2021 with a projected lifetime of 7-10 years and is implemented by the European Space Agency (ESA), the European Centre for Medium-Range Weather Forecasts (ECMWF) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). The project is entering its 2nd phase in mid 2024 and is already delivering first examples of digital-twin technology to selected users.

Peter Bauer received his PhD in meteorology from the university of Hamburg, Germany, in 1992. He joined the German Space Agency (DLR) in 1989, but was also awarded guest scientist positions at the National Atmospheric and Oceanic Administration (NOAA) and the National Aeronautics and Space Administration (NASA) in the USA, and the Institut Pierre Simon Laplace (IPSL) in France. He joined the European Centre for Medium-Range Weather Forecasts (ECMWF) in 2000, where he headed the units for satellite data assimilation and model development before becoming the deputy director of research. He implemented the Scalability Programme preparing the forecasting system for emerging super-computing technologies. He coordinated the European flagship proposal ExtremeEarth leading to his appointment as the ECMWF director for Destination Earth. During his career, Peter Bauer was a member of numerous strategic advisory committees for national meteorological services, WMO and space agencies. He retired from ECMWF in mid 2023.

Webinar was recorded on February 29, 2024 

We are now more than a full year into the era of JWST, NASA’s flagship observatory and successor to the Hubble Space Telescope. Exoplanet characterization has historically been dominated by space-based facilities, and the new infrared capabilities of JWST are uncovering the atmospheres of exoplanets in an unprecedented way. The chemical signatures of planets are being actively probed and detected, with an array of new chemical species now detectable including oxygen, carbon and nitrogen-bering molecules. This opens up spectral constrains to the rich atmospheric chemistry ongoing in a wide range of planetary types, temperatures, and metallicities. In this talk, the speaker will discuss some of the outstanding questions in the exoplanet field and how the atmospheric chemistry can help address these questions. He will also present new transit and phase curve results from ongoing JWST programs, including a Neptune and Jupiter mass planet discussing the implications of the chemistry and atmospheric physics of these planets.

David Sing is the Bloomberg Distinguished Professor of Astrophysics at the Johns Hopkins University, in the Departments of Physics and Astronomy as well as Earth and Planetary Sciences. David Sing is a worldwide expert of exoplanet science, with special interest in the detection and characterization of exoplanets, the physics and chemistry of their atmospheres, and comparative  exoplanetology studies. His research involves both observations and theoretical spectral retrieval modeling.He uses primarily  transit method data collected  by the Hubble Space Telescope and the James Webb Space Telescope to make transmission, emission and phase curve panchromatic measurements for planets from super-Earth to Neptune and Jupiter sizes.

Webinar recorded on January 25,  2024

Computer simulations of the universe have been in common use since the 1980s, and are now a vital tool in helping us interpret data from increasingly powerful telescopes. Amongst other things, simulations have helped establish the case for dark matter and dark energy, and have been key to creating a broad consensus around the idea that galaxies start small and grow over time through merging. The speaker reviews in outline how these simulations work, and highlight that a key difficulty in understanding their results is to untangle cause and effect. For example, the observed diversity of different galaxy sizes, shapes and colours can be reproduced in a statistical sense, but there is still considerable uncertainty around which causal processes give rise to this diversity. The speaker explains how exerting careful experimentation with the initial conditions for our simulations, which represent conditions shortly after the ‘big bang’, we can start to address these uncertainties. We call this technique ‘genetic modification’, since it loosely corresponds to controlling the genes of our virtual galaxies, to see how the galaxies mature and develop in response. This in turn helps to build a more complete physical picture of how galaxies mature over time, with carefully quantified uncertainties. The speaker discusses how such efforts are vital to making sense of new observations from cutting-edge and future facilities like Gaia, JWST, ELT, SKA and LISA.

Andrew Pontzen is a professor of cosmology at University College London (UCL), and is currently principal investigator of the ERC consolidator project GMGalaxies. His research concerns how structures formed in our universe, using a combination of theoretical and computational advances including the ‘genetic modification’ technique which he pioneered and which will be the focus of this talk. He was the founding co-director of the UCL Cosmoparticle Initiative which fosters interdisciplinary research, and has received multiple awards for his research and communication.  He is the author of The Universe in a Box which is a non-specialist book focussing on the role of simulations in cosmology and beyond, recently published to critical acclaim.