Jupiter's decisive role in the inner Solar System's early evolution.

Area of Science:

• Planetary Science
• Computational Astrophysics
• Solar System Formation

Background:

• Extrasolar planetary systems typically form planets with short orbital periods (<100 days) and high masses.
• The Solar System's architecture, with its low-mass terrestrial planets and lack of short-period planets, is anomalous compared to exoplanetary systems.
• A common formation scenario involves Jupiter migrating inward from beyond 5 AU to 1.5 AU before outward migration.

Purpose of the Study:

• To investigate whether Jupiter's inward migration can explain the unique characteristics of the Solar System's terrestrial planets.
• To understand the dynamical processes that shaped the inner Solar System and led to its low terrestrial planet mass and absence of close-in planets.

Main Methods:

• Computational simulations of planet formation and dynamical evolution.
• Modeling Jupiter's inward migration and its gravitational influence on planetesimals.
• Analysis of orbital resonances, collisional cascades, and gas drag effects on early planetary bodies.

Main Results:

• Jupiter's inward migration to ~1.5 AU can account for the low mass of terrestrial planets.
• This migration process explains the absence of planets within 0.4 AU.
• Migrating Jupiter's gravity excited planetesimals into resonances, triggering a cascade that depleted material and removed inner planets.

Conclusions:

• The inward migration of Jupiter is a key factor in shaping the terrestrial planet region of the Solar System.
• The terrestrial planets likely formed from a depleted debris disk after significant dynamical evolution.
• This scenario reconciles the Solar System's unusual architecture with general planet formation theories.