Probing Habitable Planets through Diamond Windows

透过钻石窥探宜居星球的奥妙

Professor Jie (Jackie) Li

University of Michigan

2024.05.23（星期四）15:30，二教306

Abstract:

Earth’s magnetic field is thought to be essential for life. The field originates in the iron-rich core through convection of molten metallic fluid, a process known as the geodynamo. Paleomagnetic records suggest that the field has been active for at least 3.5 billion years. Early in the Earth’s history, the geodynamo was likely driven by thermal convection. As the core cooled, compositional buoyancy became the principal driving force. The present-day dynamo power mainly comes from the gravitational energy released during the inner core growth. Mineral physics data and dynamic models suggest that thermal convection alone can only sustain the dynamo for the first half to one billion years of the Earth’s history and that the inner core is less than 1 billion years old. This leaves a gap of at least two billion years when the main power of the geodynamo remains poorly understood. In this talk, I will showcase recent experimental investigations of material properties at extreme conditions and discuss the implications for habitable planets.

Bio:

Jie (Jackie) Li is the Rodney C. Ewing Collegiate Professor of Earth and Planetary Sciences in the Department of Earth and Environmental Sciences at the University of Michigan. Li's research focuses on material properties and planetary differentiation, with an emphasis on high-pressure behavior and formation of habitable worlds. Li received a PhD in Earth and Planetary Sciences from Harvard University. Li is an author of more than 80 peer-reviewed papers. Li gave more than 100 invited lectures in many countries including US, Japan, China, Germany, Switzerland, and Australia. Li is an elected fellow of the American Association for the Advancement of Science (AAAS) since 2022, a Kavli Fellow of the National Academy of Sciences in 2013, a Tharp Fellow at Columbia University in 2012, and an elected Fellow of the Mineralogical Society of America since 2010. Currently Li serves as an Editor-in-Chief of the Elsevier Journal Physics of Earth and Planetary Interiors, a Science Advisor of the American Geophysical Union (AGU) EoS magazine, and on the Executive Committee of the College of Literature, Science, and the Arts at the University of Michigan.