演講資訊

摘要：

Terrestrial planets have traditionally been thought to form by collisions between protoplanets taking place mostly after the dissipation of the protoplanetary disc, on time-scales of 30-100 million years. I present here a new theoretical model where terrestrial planets grow instead by accreting small pebbles in the protoplanetary disc within 3-5 million years. I discuss how the immense pebble accretion heat leads to extensive melting of the growing planets and to the emergence of deep magma oceans. The end of the accretion phase leads to rapid crystallisation of the magma ocean and outgassing of the first atmosphere. I will show how the atmospheric composition of young planets is key to understanding the origin of life.