Europlanet Science Congress 2020
Virtual meeting
21 September – 9 October 2020
Europlanet Science Congress 2020
Virtual meeting
21 September – 9 October 2020

Poster presentations and abstracts

EXO3

Since the discovery of the first exoplanet in 1995 more than 4000 exoplanets have been detected to date. This indicates that planet formation is a robust mechanism and nearly every star in our Galaxy should host a system of planets.
However, many crucial questions about the origin of planets are still unanswered: How and when planets formed in the Solar System and in extra-solar systems? Are protoplanetary disks massive enough to form the planets cores? And what chemical composition do planets and primitive Solar System bodies inherit from their natal environment? Is the chemical composition passed unaltered from the earliest stages of the formation of a star to its disk and then to the bodies which assemble in the disk? Or does it reflects chemical processes occurring in the disk and/or during the planet formation process?

A viable way to answer these questions is to study the planets formation site, i.e. protoplanetary disks. In the recent years, the advent of ALMA and near-infrared/optical imagers aided by extreme adaptive optics revolutionised our comprehension of planet formation by providing unprecedented insights on the protoplanetary disks structure, both in its gaseous and solid components.
The aim of this session is to review the latest results on protoplanetary disks; to foster a comparison with the recent outcomes of small bodies space missions (e.g. Rosetta, Dawn, Hayabusa 2, OSIRIS-REX) and ground-based observations; and to discuss how these will affect the current models of planet formation and can guide us to investigate the origin of planets and small bodies and of their chemical composition.

Co-organized by SB
Convener: Linda Podio | Co-conveners: Mauro Ciarniello, Cecile Favre, Carlo Felice Manara, Francesco Marzari

Session assets

Session summary

Chairperson: Linda Podio
EPSC2020-604ECP
Artyom Aguichine, Olivier Mousis, Bertrand Devouard, and Thomas Ronnet

In our solar system, terrestrial planets and meteoritical matter exhibit various bulk compositions. To understand this variety of compositions, formation mechanisms of meteorites are usually investigated via a thermodynamic approach that neglect the processes of transport throughout the protosolar nebula. Here, we investigate the role played by rocklines (condensation/sublimation lines of refractory materials) in the innermost regions of the protosolar nebula to compute the composition of particles migrating inward the disk as a function of time. To do so, we utilize a one-dimensional  accretion disk model with a prescription for dust and vapor transport, sublimation and recondensation of refractory materials (ferrosilite, enstatite, fayalite, forsterite, iron sulfur, kamacite and nickel). We find that the diversity of the bulk composition of cosmic spherules can be explained by their formation close to rocklines, suggesting that solid matter is concentrated in the vicinity of these sublimation/condensation fronts. Although our model relies a lot on the number of considered species and the availability of thermodynamic data governing state change, it suggests that rocklines played a major role in the formation of small and large bodies in the innermost regions of the protosolar nebula. The results of our model are consistent with the composition of chondrules and cosmic spherules. Our model gives insights on the mechanisms that might have contributed to the formation of Mercury's large core.

How to cite: Aguichine, A., Mousis, O., Devouard, B., and Ronnet, T.: Rocklines of high temperature minerals in the protosolar nebula, Europlanet Science Congress 2020, online, 21 Sep–9 Oct 2020, EPSC2020-604, https://doi.org/10.5194/epsc2020-604, 2020.