Speaker: MAX COLLINET, GERMAN AEROSPACE CENTER (DLR), BERLIN Title: Achondrites as witnesses of early melting processes in planetesimals and planetary embryos: experimental constraints and new meteorite discoveries Abstract: Achondrite meteorites are highly variable in composition: some are ultramafic (primitive achondrites) while others are basaltic (e.g. eucrites and angrites), to trachy-andesitic (e.g. GRA 06128 and Erg Chech 002). Those different groups correspond to the mantle and crust of planetary building blocks, respectively. They represent a unique opportunity to constrain the early melting processes that affected planetesimals and could have influenced the final composition of planets. I will describe two sets of low pressureContinue reading

Speaker: ANDERS JOHANSEN, UNIVERSITY OF COPENHAGEN Title: Formation of terrestrial planets by pebble accretion Abstract: The formation of the terrestrial planets in the Solar System is normally considered to last several 10s of million years and to have proceeded by giant impacts within a population of Mars-sized protoplanets. Observations of protoplanetary discs around young stars reveal that such discs host several hundred Earth masses of mm-cm sized pebbles. This inspired the pebble accretion theory for planet formation where the cores of giant planets grow by rapid accretion of these pebbles. By extension, pebble accretion should be an important process inContinue reading