Solar System Migration Points to a Renewed Concept: Galactic Habitable Orbits

TL;DR

This paper explores how the Sun migrated from its birth location to its current orbit using simulations of galactic dynamics, proposing the concept of 'Galactic habitable orbits' and examining environmental impacts on habitability.

Contribution

It introduces the idea of 'Galactic habitable orbits' and demonstrates two plausible migration pathways for the Sun, linking galactic dynamics to planetary habitability.

Findings

Both migration mechanisms can explain the Sun's current position.

Migration pathways influence environmental hazards affecting habitability.

The concept of 'Galactic habitable orbits' highlights the importance of galactic dynamics for life potential.

Abstract

Astrophysical evidence suggests that the Sun was born near 5 kpc from the Galactic center, within the corotation radius of the Galactic bar, around 6-7 kpc. This presents challenges for outward migration due to the Jacobi energy constraint, preventing stars from easily overcoming the corotation barrier. In this study, we use test particle simulations to explore two possible migration pathways for the Sun: a "trapped" scenario, where the Sun's orbit was influenced by a slowing Galactic bar, and an "untrapped" scenario driven by dynamic spiral arms. Our results demonstrate that both mechanisms can explain how the Sun migrated from its birth radius (approximately 5 kpc) to its current orbital radius around 8.5-9 kpc. Furthermore, we investigate the environmental changes experienced by the Sun along these migration pathways, focusing on variations in radiation hazards and comet fluxes, which may have impacted planetary habitability. These findings highlight the dynamic nature of galactic habitability, emphasizing that the path a star takes within the Milky Way can significantly affect its surrounding environment and the potential for life. We propose a new concept of "Galactic habitable orbits," which accounts for evolving galactic structures and their effects on stellar and planetary systems. This work contributes to a deeper understanding of the solar system's migration and its implications for habitability within the Milky Way.