11:30 AM - 11:45 AM
[PPS06-14] Modeling Contact Surface between Colliding Pebbles and Its Application to Comet Formation
Keywords:comets, comet formation, planetesimal formation, dust aggregates, strength, 67P/Churyumov-Gerasimenko
To understand the process of planetesimal formation, explorations of small Solar System bodies, considered as remnants of planetesimals, have been conducted. Among these bodies, comets are particularly believed to be aggregates of millimeter- to centimeter-sized pebbles, which are composed of densely packed submicron-sized dust particles, as suggested by their low tensile strength and other characteristics (e.g., Blum et al. 2022). Contact areas are formed between pebbles, which play a critical role in determining the tensile strength of the pebble aggregates. These contact areas depend on the internal density of the pebbles and the collision velocities at the time of adhesion. Therefore, by inversely estimating these factors from the tensile strength observed in comet exploration, it is possible to reveal the formation processes of comets.
In this work, we estimated the collision velocities between pebbles during the formation of comet 67P/Churyumov-Gerasimenko by using a contact area model derived from the compressive strength of dust aggregates (Tatsuuma et al. 2023). The tensile strength of 67P is 1.5-100 Pa (Basilevsky et al. 2016). By applying the tensile strength of dust aggregates (Tatsuuma et al. 2019), we calculated the contact area between pebbles and derived the collision velocities required to achieve this contact area. Our results suggest that the collision velocities are below several cm/s. In this talk, we will also discuss the validity of such low-velocity pebble accretion in the context of comet formation.
In this work, we estimated the collision velocities between pebbles during the formation of comet 67P/Churyumov-Gerasimenko by using a contact area model derived from the compressive strength of dust aggregates (Tatsuuma et al. 2023). The tensile strength of 67P is 1.5-100 Pa (Basilevsky et al. 2016). By applying the tensile strength of dust aggregates (Tatsuuma et al. 2019), we calculated the contact area between pebbles and derived the collision velocities required to achieve this contact area. Our results suggest that the collision velocities are below several cm/s. In this talk, we will also discuss the validity of such low-velocity pebble accretion in the context of comet formation.