Speaker: Peter Driscoll

Host: Doug Hemingway

Abstract: Planetary magnetic fields offer the first barrier between atmospheres and the solar wind, and are expected to play a central role in long-term habitability.  In this talk we discuss why planetary magnetic fields are important to planetary habitability and how they change over billions of years of planetary evolution.  We discuss the ubiquity of planetary magnetic fields in the Solar System and the prospects for detecting exoplanet magnetic fields.  We review the requirements for magnetic field generation by dynamo action, general limits to thermal dynamo action, and how the planetary cooling rate affects magnetic field evolution.  We will highlight how Earth’s magnetic field has evolved over the last 2 billion years, and how paleomagnetism and dynamo theory can be used in tandem to infer the dynamical evolution of the deep interior.