Space Science seminars

Planets form from dust embedded in gaseous protoplanetary disks. Hydrodynamic instabilities can hinder growth by stirring turbulence, yet also help by creating structures that collect solids and promote planetesimal formation. Min-Kai Lin will discuss analytical and numerical studies of the vertical shear instability and convective overstability, their interactions with dust, and generalisations of the streaming instability to disks with accretion or magnetic fields. The seminar examines how these processes alter the conditions for concentrating solids and the challenges that remain in connecting disk dynamics to planet formation.

Public lecture by Prof. Didier Queloz, FRS (Jacksonian Professor of Natural Philosophy, Cambridge; Professor of Physics, ETH Zurich), organized by the Swiss Physical Society at EPFL, on how exoplanet discoveries transformed understanding of planet formation and the search for life signatures in planetary atmospheres. Free admission for the general public.

This seminar examines comet impacts during the dispersal of the outer Solar System's planetesimal disk. Instability among the giant planets sent some bodies toward the terrestrial planets. Noble gases preserved in Earth's atmosphere provide evidence for the scale of this bombardment and help relate its timing to the growth of Earth.

This lecture tests whether the Nice model can account for the detailed architecture of the Kuiper belt. It contrasts Neptune's behaviour during planetary instability with simpler gradual-migration scenarios. The distribution of distant small bodies provides constraints on the dynamical history of the giant planets.

When did the giant planets become dynamically unstable? This lecture compares evidence from lunar impact craters, binary objects in the Kuiper belt and dynamical models. It explains why these constraints matter for reconstructing Solar System evolution and why the timing remains an unresolved research question.

This seminar introduces the physical properties of Jupiter's Trojan asteroids and the scientific aims of NASA's Lucy mission. It reviews the mission's planned encounters as described at the time of the talk. It also discusses the 2023 discovery of a binary asteroid whose companion has a contact-binary structure.

This lecture connects the properties of the giant planets to their diverse populations of moons and co-orbiting small bodies. It focuses on irregular satellites, whose inclined and elongated orbits suggest capture, and on Trojan objects that move around stable configurations associated with Jupiter or Neptune.

This lecture traces the origins of different comet populations and the processes that send them into the inner Solar System. It compares the scattered Kuiper-belt reservoir with the distant Oort cloud. It also examines the evidence and debate surrounding a possible additional planet beyond Neptune.

The Kuiper belt contains a complex collection of bodies beyond Neptune, including Pluto. This lecture compares dynamically cold and excited populations, resonant objects, scattered bodies and detached remnants. Their orbital structure provides a record of the Solar System's past evolution.

This lecture follows the growth of planets from an initial population of planetesimals. It examines collisions that build protoplanets, the accretion of smaller particles and mergers between growing bodies. Some sufficiently massive objects also capture surrounding gas, producing different classes of planets.

This lecture examines how dust in a young circumstellar disk becomes large solid bodies. Collective particle motion and its interaction with gas can concentrate material into gravitationally bound clumps. Their collapse offers a route to planetesimals, whose surviving descendants include asteroids and trans-Neptunian objects.

Didier Queloz traces the transformation of planetary science following the 1995 discovery, with Michel Mayor, of a giant planet orbiting another star. Thousands of subsequent discoveries have revealed planets ranging from gas giants to smaller rocky bodies, stimulated new instruments and changed theories of planetary formation and evolution. The diversity of exoplanet systems challenges assumptions drawn from the Solar System and raises questions about how common systems like ours are. The lecture also considers the possibility of searching planetary atmospheres for evidence of life.

Julie Robinson explores what maintaining human life aboard the International Space Station teaches us about Earth. Space habitation requires engineered substitutes for the air, water, surfaces and living systems that our planet supplies. Long-duration occupation of the station has produced lessons about building and operating these life-support systems. The station is also an observing platform for the Earth system below. Robinson connects the engineering lessons of living in space with Earth observations, climate change, and ways that spaceflight can help communities understand environmental change and strengthen their resilience.

What happens to human sleep and circadian rhythms in space? There are many challenges that affect sleep in space, including unusual patterns of light exposure and the influence of microgravity. This talk will review the causes and consequences of sleep loss and circadian misalignment during spaceflight and will discuss how missions to the Moon and Mars will be different than missions to the International Space Station.

The presentation will present the work of the Space Enabled Research Group at the MIT Media Lab. The mission of the Space Enabled Research Group is to advance justice in Earth’s complex systems using designs enabled by space. Our message is that six types of space technology are supporting societal needs, as defined by the United Nations Sustainable Development Goals. These six technologies include satellite earth observation, satellite communication, satellite positioning, microgravity research, technology transfer, and the infrastructure related to space research and education. While much good work has been done, barriers remain that limit the application of space technology as a tool for sustainable development. The Space Enabled Research Group works to increase the opportunities to apply space technology in support of the Sustainable Development Goals and to support space sustainability. Our research applies six methods, including design thinking, art, social science, complex systems, satellite engineering and data science. We pursue our work by collaborating with development leaders who represent multilateral organizations, national and local governments, non-profits and entrepreneurial firms to identify opportunities to apply space technology in their work. We strive to enable a more just future in which every community can easily and affordably apply space technology. The work toward our mission covers three themes: 1) Research to apply existing space technology to support the United Nations Sustainable Development Goals; 2) Research to design space systems that are accessible and sustainable; and 3) Research to study the relationship between technology design and justice. The presentation will give examples of research projects within each of these themes.