Challenges in Planet Formation

TL;DR

This paper reviews five key challenges in understanding planet formation, highlighting unresolved issues in disk structure, planetesimal growth, migration, orbital architecture, and exoplanet relationships, which hinder the development of comprehensive models.

Contribution

It provides a comprehensive review of fundamental bottlenecks in planet formation, emphasizing areas where current understanding is limited and future research is needed.

Findings

Identification of five major bottlenecks in planet formation.

Highlighting the gaps in current models due to unresolved issues.

Emphasizing the need for further research to understand planetary system architectures.

Abstract

Over the past two decades, large strides have been made in the field of planet formation. Yet fundamental questions remain. Here we review our state of understanding of five fundamental bottlenecks in planet formation. These are: 1) the structure and evolution of protoplanetary disks; 2) the growth of the first planetesimals; 3) orbital migration driven by interactions between proto-planets and gaseous disk; 4) the origin of the Solar System's orbital architecture; and 5) the relationship between observed super-Earths and our own terrestrial planets. Given our lack of understanding of these issues, even the most successful formation models remain on shaky ground.