Published online by Cambridge University Press: 19 April 2010
ALMA will observe extrasolar planetary systems in various stages of formation. From young, planet-forming (protoplanetary), dusty disks, to mature solar-system analogs, ALMA will produce transformational science. We investigate the imaging capabilities of ALMA to infer structure in protoplanetary disks created by a protoplanet, as well as possible direct detection of the protoplanet itself. In addition, ALMA will be able to perform high-accuracy astrometry of main sequence stars, allowing us to search for the astrometric wobble caused by orbiting planets.