Quantifying Jupiter's influence on the Earth's impact flux: Implications for planetary habitability

TL;DR

This study uses dynamical simulations to explore how Jupiter's mass and orbit influence Earth's impact rate, revealing that Jupiter may increase impact risks rather than solely shielding Earth, thus affecting planetary habitability.

Contribution

It provides new insights into Jupiter's complex role in impacting Earth's impact flux, challenging the traditional view of giant planets as mere shields.

Findings

Jupiter's influence on impact flux is more complex than previously thought.

Jupiter can increase impact risk to Earth depending on its orbit and mass.

The role of giant planets in habitability is nuanced and not solely protective.

Abstract

It has long been thought that the presence of a giant planet is a pre-requisite for the development of life on potentially habitable planets. Without Jupiter, it was argued, the Earth would have been subject to a punishing impact regime, which would have significantly retarded or outright prevented the development of life on our planet. Although this idea is widely embraced, little research has previously been carried out to support it. Here, we present the results of several suites of dynamical integrations used to model the influence of Jupiter's mass and orbit on the impact rate that would be experienced by the Earth. We find that, far from being a simple shield, Jupiter's role in determining the terrestrial impact flux is significantly more complicated than previously thought. Far from being a simple friend, such giant planets are perhaps more likely to imperil the development of life on otherwise habitable planets.