Professor George Rieke led the development of the MIPS instrument for Spitzer and now leads the science team of the Mid-Infrared Instrument for JWST. His current science is focused on the capabilities of these instruments. The MIPS instrument team has documented the incidence, properties, and evolution of planetary debris disks around nearby stars. Debris disks are perhaps the best way to study planetary system evolution after a system emerges from its protoplanetary disk. The team has also demonstrated that nearly half of the active nuclei in distant galaxies are missing in deep X-ray catalogs, but can be identified through infrared observations. Rieke's plans for JWST investigations include imaging nearby debris disks to understand how their structures are sculpted by planet systems and to study the interplay between AGN and host galaxy star formation.