The solid content of circumstellar disks is inherited from the interstellar medium: dust
particles of at most a micrometer in size. Protoplanetary disks are the environment where …

This chapter reviews the estimates of the dust-to-gas and refractory-to-ice mass ratios
derived from Rosetta measurements in the lost materials and the nucleus of 67P/Churyumov …

Geochemical and astronomical evidence demonstrates that planet formation occurred in two
spatially and temporally separated reservoirs. The origin of this dichotomy is unknown. We …

Context. The global size and spatial distribution of dust is an important ingredient in the
structure and evolution of protoplanetary disks and in the formation of larger bodies, such as …

Laboratory experiments indicate that direct growth of silicate grains via mutual collisions can
only produce particles up to roughly millimeters in size. On the other hand, recent …

Rapid orbital drift of macroscopic dust particles is one of the major obstacles to planetesimal
formation in protoplanetary disks. We re-examine this problem by considering the porosity …

Aims. We attempt to explain grain growth to mm sized particles and their retention in the
outer regions of protoplanetary disks, as observed at sub-mm and mm wavelengths, by …

Context. The formation stage of planetesimals represents a major gap in our understanding
of the planet formation process. Late-stage planet accretion models typically make arbitrary …

Accumulation of dust and ice particles into planetesimals is an important step in the planet
formation process. Planetesimals are the seeds of both terrestrial planets and the solid cores …

Context. Transition disks are believed to be the final stages of protoplanetary disks, during
which a forming planetary system or photoevaporation processes open a gap in the inner …