Event DetailsEvent Dates: Friday, November 13, 2015 - 12:00pmSeminar Location: JILA 10th Floor - Foothills RoomSpeaker Name(s): Peter WilliamsSpeaker Affiliation(s): Harvard-Smithsonian Center for Astrophysics Seminar Type/SubjectScientific Seminar Type: Astrophysics Lunch SeminarEvent Details & Abstract: The magnetic field of Earth protects its surface from cosmic rays and the solar wind, while that of Jupiter enables powerful aurorae that can be brighter than the Sun at long radio wavelengths. What are the magnetospheres of extrasolar planets like? Although direct observations are not yet feasible, the groundwork for answering this question is being laid, with an ultimate goal of characterizing magnetic properties across the spectrum of exoplanet types and even peering "inside" rocky planets to identify which ones may be geologically active. I will discuss recent exciting developments in our understanding of the magnetic properties of very low-mass stars and brown dwarfs, which turn out to be surprisingly similar to those of the Solar System planets, as well as prospects for the truly exoplanetary regime. The future is especially bright because radio studies of planets have very similar technical needs to those of the Epoch of Reionization, which are seeing substantial investment. In particular, I argue that HERA, the under-construction Hydrogen Epoch of Reionization Array, will be the best tool on the planet for delivering breakthrough results not only in reionization, but also in the nascent field of exoplanetary magnetospheric studies.