I will kickstart the seminar!

Most small bodies with sizes larger than tens of meters are made of numerous pieces of rocks and sometimes ices that have coalesced under the influence of gravity (so called “rubble piles”).  As their own gravity is not enough to squeeze them into spheres, these small bodies exhibit a variety of shapes and surface morphologies, recording their life stories.  Here I will show by numerical simulations how small bodies are reshaped in general subject to various effects, e.g., collisions, solar radiation, close encounters, based on our recent studies.  Our interpretations allow us to characterize their physical properties and constrain their formation and evolution.  Some examples including the formation of the first discovered interstellar object ‘Oumuamua will be given (Zhang & Lin, Nature Astronomy, 4, pp. 852–860, 2020).