Abstract

The building blocks of planets are the dust, gas, and ice in the protoplanetary disks orbiting young stars. Deep, high resolution images of protoplanetary disks by ALMA have revealed complex and varied ring and spiral structures in a number of systems. In the Disk Substructures at High Angular Resolution Project (DSHARP), we undertook the first high angular resolution disk survey at millimeter wavelengths. DSHARP found that gaps and rings indicative of planet-disk interactions were widespread, implying that giant planet formation proceeds rapidly even at tens of au from the star. On the other hand, the origins of “grand design” millimeter continuum spiral arms are more enigmatic, and may point either to disk instabilities or the formation of super-Jovian planets at surprisingly wide separations. Gaps and rings are also common in molecular emission, and appear primarily to result from vigorous chemical reprocessing in the disk. Finally, recent discoveries of irregular, extended structures in CO emission in several systems suggest that the planet formation environment may be disrupted by exchange of material between disks and their surroundings. Together, these new data show that the natal environments of planets are far more dynamic and diverse than earlier observations have indicated.